Oral History Transcript — Dr. Ralph Baldwin

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Ralph Baldwin; October 25, 1989

ABSTRACT: Early schooling and university training; association with the Oliver Machinery Company; involvement in the Applied Physics Laboratory of the Johns Hopkins University during World War II; lunar studies from the 1940s into the 1970s. Recollections of professional employment at the Flower Observatory of the University of Pennsylvania in the 1930s, and the Dearborn Observatory of Northwestern University from 1938 to 1942.

Transcript

Doel:

I know that you were born on June 6, 1912 in Grand Rapids but I really don't know anything else about your family or your early life. What did they do?

Baldwin:

My father was an engineer. He was the second member of the family to attend the University of Michigan and was graduated in 1908. His father, Frank A. Baldwin, was a Class of 1877 Law at the University. I am third generation and I have two children out of three who were graduated from the University. I didn't mention my father's name was Melvin D. Baldwin. My mother, Julie Belknap Baldwin, went to Michigan State. Mother and Dad were world travelers at a time when it wasn't really a popular thing to do. They took the most unusual trips, like flying the Pacific in the 1950s in a DC4 and taking the boat trip up the Orinoco River — things that nobody else did. Dad lived to be 92; mother 96.

Doel:

That is remarkable.

Baldwin:

Well, it was except that my father's mother — Grandmother Baldwin — lived to be 101. I have a lot to live up to and I don't know whether I can do it or not.

Doel:

Can you tell me a little more about the travels they took? Were they simply pleasure trips or were they related to your father's business?

Baldwin:

No, not business. When I was ten years old we drove to Yellowstone Park and then through the Teton area of Jackson Hole and down to Salt Lake City and back. There wasn't a paved road west of Chicago. We drove — in 1922 — in a 1918 Nash Touring Car, which Dad's engineering talents allowed him to cobble up ways of carrying everything we'd need for that seven week trip. It was an experience and I never forgot it.

Doel:

What kind of engineering did your father do?

Baldwin:

He was a mechanical engineer. He utilized his training throughout his career in business.

Doel:

Did you have brothers and sisters?

Baldwin:

One sister. Her name is Frances Elizabeth Baldwin Mulnix. She is living in Grand Rapids now with her husband, her children, her grandchildren and great grandchildren.

Doel:

Did she have a career in science at all?

Baldwin:

No. She was a graduate of Michigan State University. Her field was Home Economics and she utilized that regularly.

Doel:

Your family for generations has had strong ties with the University of Michigan. Did your parents or previous generations, were they involved in the university in other capacities?

Baldwin:

Financially they have always supported the University and Michigan State. The University of Michigan has a group which was called the Presidents Club at the time my father joined whereby with a certain minimum contribution you became a member, he and mother were each members. They would go down to the University several times per year to participate in some university function, and occasionally go to a football game.

Doel:

How many generations has your family been in the United States?

Baldwin:

I would have to go back and count, but I think I am the tenth. So that would bring it up to thirteen generations total, through my sister's children. The family ancestors were not smart enough to catch the Mayflower but they came six or eight years later to Massachusetts.

Doel:

I would say they caught on pretty fast. Could you describe your home life and how you feel about it, and about early interests?

Baldwin:

My grandmother — Nellie Baldwin — was one of the most intelligent, well-read women I ever knew. She was no astronomer but she did know the constellations and when I was just a little fellow she took me out repeatedly and would show me Orion, the Big Dipper, red Aldebaran and things like that. I am sure she deliberately created an interest in astronomy for me. She was also a world traveler although she and grand-dad went on more standard type trips than Mother and Dad. Grandma was the grande dame — the great lady. She knew everybody in Grand Rapids and thereabouts who was anybody and was quite socially inclined. But beyond that she was, well I never went there but what I learned something new. I think that is a about as good a way to put it as any.

Doel:

Did she encourage you to read?

Baldwin:

Yes.

Doel:

What books in particular made an impression?

Baldwin:

I have all of them back in my library in Grand Rapids. In fact, I had to build a separate room in the house for parts of the library beyond what is up in the regular library. There was a whole series of astronomical books. There was a book by Simon Newcomb. I haven't thought of these individual books for years. I have one in the 1700s by one of the Herschels. She encouraged me to get a small telescope and I got a Bardou — a French make — 3" achromatic refractor. I had various books to go with that. The Norton Star Atlas, and the name gets away from me but there is another one where there is a paragraph or two on everything you can see in small telescopes — what to look for, how to find them.

Doel:

Something like Burnham's Handbook?

Baldwin:

No. Webb I think the man's name was. Celestial Objects for Small Telescopes or something in that ball park. I kept on reading and observing. My parents never knew whether I was in bed or out in the front yard with the telescope.

Doel:

How old were you when you got that first telescope?

Baldwin:

It must have been somewhere around when I was 10 or 11, because I had it all through high school and I had it some period of time before that. It was a nice instrument. I have always regretted selling it after I went to college. I figured I would always be in an observatory and have telescopes available. It didn't work out that way.

Doel:

I'm curious: were there other people you had a chance to talk to about astronomy when you were in high school, as your interests were developing?

Baldwin:

Mother and Dad contacted the observatory director at Ann Arbor and on a few occasions I went down to visit. The man that I talked to most was Dr. W. Carl Rufus. He and Mrs. Rufus became family friends and visited us in Grand Rapids, and we visited them. They came to our wedding in 1940 over in Evanston. They were fascinating people. They had been missionaries in Korea, as young people. How he got into astronomy I don't know but they were a lot of fun to be around. She was an airplane pilot and later was actually killed in a crash where she got some bad gasoline for a take-off. She wrote a book called Flying Grandma.

Doel:

When your parents took world trips, did you accompany them on any of their longer trips?

Baldwin:

Only twice. In 1922 — as I mentioned earlier — we went to Yellowstone Park and my sister and I drove with Mother and Dad. In 1936 we took a ship, including the car, to Buffalo and then took the 1000 Island trip down the St. Lawrence and finally got off at — I've forgotten whether it was Montreal or Quebec — and then drove around the Gaspe Peninsula and back. That was a very lovely trip and I thoroughly enjoyed it. One of my most vivid memories of that is being on the boat called the Tadousac — the cruise boat for the river only. We went past the Empress of Britain, which was a 40-50,000 ton, all-white ship that later was sunk in the War. We passed 100 feet or so from that huge, glorious ship.

Doel:

I sense it did make a strong impression on you. You remember the name.

Baldwin:

I have a very good memory at times but at other times it is just awful. It is getting worse as I get older.

Doel:

I am curious, too, did you have experience and interest in geology as well during that time you were in high school?

Baldwin:

Not to the extent of going out and doing things but I did read a good deal of geology. I took a course in Ann Arbor from a great big, red-headed giant of a man — I can't think of his name now. It'll come to me. [Added later by Baldwin: William H. Hobbs]. As a result of that I did a good deal of reading and I have a series of geology books by Zumberge and Holmes, and there are four or five others. So, I had the equivalent of a freshman or sophomore in college training in geology, but largely self-taught.

Doel:

But you didn't, you weren't collecting minerals or anything like that?

Baldwin:

No.

Doel:

Do you remember — speaking of high school — any particularly influential teachers you met during that time?

Baldwin:

I think the most influential teacher that I ever had was in about my sophomore year. I took a course in Algebra from her and she flunked me! She told Mother; she said "I had to flunk Ralph." I didn't agree with it. She said "He never would turn in his homework, and then he would get A's on the test." So I took it over in summer school. Mrs. Wilson.

Doel:

I imagine you can remember that name. You found then that mathematics came to you fairly naturally?

Baldwin:

I had little trouble with mathematics until I got into vector analysis in college. Then I had to work like a dog and it never really sank in the way it should. I can handle most ordinary mathematics even today but I have to stop now and analyze what I am doing pretty carefully.

Doel:

I should point out on tape that you attended the Central High School in Grand Rapids.

Baldwin:

Yes.

Doel:

And that was a public high school?

Baldwin:

It is a public high school and we had a good deal of loyalty to that school even to this day — and I was in the class of 1930 — a group, which is still about 20, meets seven times a year for lunch up in Grand Rapids. I am going back there next month and I hope and think that they will have one of their meetings during that period.

Doel:

That is interesting. One doesn't hear about that so often.

Baldwin:

I don't know any other class that does that but this group has stuck together.

Doel:

So there was really no doubt in your mind, when you were finishing high school that you were going to go to the University of Michigan?

Baldwin:

In the Helios, which was the annual publication of the high school, under my picture was a statement that "Ralph was going to take up star gazing at the University of Michigan."

Doel:

That is interesting. It was clear then to many people that you had an interest in astronomy. You were certain that that was your career choice?

Baldwin:

Yes I was. I have never regretted it. It is a hard life. Astronomers are not paid what they work for and even the best of them now are probably not getting more than about $60,000, which is a lot of money but that is the best.

Doel:

Did your parents encourage you to go into astronomy? Was it clear to them also?

Baldwin:

They did. They never would make a decision for me. They insisted that I make my own choices. But once I made a choice they backed it and never were in opposition. I think Dad was disappointed that I didn't want to come into the company — the manufacturing company, Oliver Machinery Company — with him. Well it turned out many years later that I did, but I had a good many years away from home. Counting my college years I was away from home 16 years, away from Grand Rapids.

Doel:

It's interesting you say that. I didn't realize your father was connected with Oliver as well.

Baldwin:

My family and one other family bought the Oliver Machinery Company in 1918. It had been in existence since 1890 and my grandfather was the first president, my father was the second, and I was the fifth president of the company after the purchase. I became president in 1970. I am still chairman of the board, though I don't even own any stock in the company anymore.

Doel:

Let me continue on with your entering at the University of Michigan. Of course, 1930 was a difficult time for people to think about going to the University for study. How did you support yourself in your undergraduate degree?

Baldwin:

I didn't. My father supported me, and while Dad was vice-president of the company at that time, his salary was minuscule, but he borrowed — he didn't steal but he did almost everything else — to pay for my college education and that of my sister. I can remember one time in my sixth year at Ann Arbor; I had applied for a fellowship and didn't get it. Nothing came in the mail. I finally went down there and went immediately to the Dean's office and asked him — since I hadn't heard either yes or no — what the situation was. He went and looked it up and said "Well, you were awarded that fellowship — it's $550." Apparently the letter got lost in the mail because others had received their letters and I figured, well for that I can use a long distance telephone and call home. And after the telephone call Dad turned to Mother and said "That is the biggest money I ever saw." He walked to work — put his car up — three miles and back. He'd have a milk shake for lunch but he kept his family together and he took care of his children.

Doel:

What was the situation at the University like during those years? How deeply affected was the University?

Baldwin:

The University enrollment at that time was about 10,000 students. There were substantial numbers that were there on scholarships and fellowships because the University — in the good times which had preceded the Depression — had accumulated monies for scholarships and fellowships and there were private funds which did not depend on current earnings, too much, where people could get scholarships. Those who really wanted to go to a university — I don't mean just Michigan — could get help. In many cases the help was sufficient to be the decisive factor. That $550 was only about half of what I actually had to pay during that year. My first year down there in 1930-31, Dad told me later that it costs $1,001. He wanted to know what I did with that $1.00! When inflation is taken into account that is not out of line with what people are paying now.

Doel:

$500 at that time was a substantial amount of money and I can appreciate how much of a sacrifice that still was for your parents. Was your sister going to school at just about the same time?

Baldwin:

She is four years younger than I am. So they had a double burden. She only took four years so we had a two year overlap. I took seven years.

Doel:

Of course you had gone on directly to the Ph.D. You still finished in four years for your undergraduate degree?

Baldwin:

Yes, right.

Doel:

Had you known any of the faculty in astronomy at Michigan before?

Baldwin:

I had met all of them.

Doel:

Had you?

Baldwin:

Yes. I told you about Dr. Rufus. But I did not really know the director, Heber Curtis and Dean McLaughlin who later was my thesis director. There was Allen D. Maxwell and a man from Canada — Robert Petrie. Then, Robley Williams. He is the one who developed the process for aluminizing telescope mirrors. As far as I know Robley is the only one still alive.

Doel:

I think that is right. Do you recall interactions in particular with any of them during your undergraduate years?

Baldwin:

During the undergraduate?

Doel:

Yes.

Baldwin:

Oh I forgot another one — Hazel Losh. Yes, we did. Hazel had a rather big office and they put a desk in that office for me about my senior year and I shared that room with her for four years. Hazel was not a research-inclined individual but she was a very fine teacher, very popular. She had a rule, A for athletes, B for boys, and C for girls — in the grading. I don't think it's quite right but that was the reputation that she had and people for 50 years flocked into her courses until toward the end she was filling an auditorium for her lecture courses.

Doel:

Did others on the faculty teach on so broad level at the university? Say Curtis?

Baldwin:

I guess they each took a turn at the elementary courses. But primarily they were teaching the advanced courses in astrophysics, celestial mechanics, etc. Curtis taught some relativity and that caliber of thing.

Doel:

Did you have an idea by the time you were in your senior year that you wanted to stay at Michigan or did you consider offers or possibilities of attending other universities?

Baldwin:

Frankly I am not sure. I think it was just assumed that I would stay at Michigan. It might have been better for a broader experience for me to have gone some other place, like Yerkes or Harvard. If I had done that I am very much inclined to think that I wouldn't have had the experiences I have had since. I am thankful that I did stay at Michigan. It was my contact with Robley Williams that allowed me to go to the Applied Physics Laboratory during World War II. It was due to Heber Curtis that I got the position before the war at Northwestern University and if I hadn't been there I doubt if I would have ever gotten into the work on the Moon.

Doel:

That wasn't an interest, or was it, that developed during your undergraduate years?

Baldwin:

The moon?

Doel:

Yes.

Baldwin:

No.

Doel:

Did you have any thoughts about lunar research.

Baldwin:

Yes. I didn't like the dog-gone thing. It got in the way. The light of the moon. It bothered every kind of observation that I wanted to make. As far as I was concerned they could have declared it illegal and made it retroactive for 30 years.

Doel:

Who would you say was among the most influential — this is again during your undergraduate years — of the science teachers you had? Any one person come to mind?

Baldwin:

It depends on influential in what way. McLaughlin and Curtis taught me the value of accurate observation and accurate reporting and to use imagination but never go beyond the possibilities of your data. I think in a fundamental sense that was probably as important as anything I learned.

Doel:

Can you think of an example?

Baldwin:

Yes, I am but I'll tell you and then we can discuss whether it should be contained or not. From one professor I took a course in celestial mechanics. Celestial mechanics involved the calculation of orbits and he was particularly interested in comets. To calculate what they call an osculating orbit you need three observations of right ascension, three of declination and three of time. If those observations are perfect you can calculate the exact orbit the comet was following at the mid-point. It immediately begins to differ from that because of the effects of the planets — the perturbations. I don't know how it came about but a certain comet was discovered and the three observations were furnished to the university and we decided that I would calculate the orbit and take into account the perturbations of Venus, the Earth, Mars and Jupiter — of which Jupiter's were far greater than any other. A book of tables had been published from which I could take the data which would allow these perturbations to be determined. The professor taught me how to use the book, I calculated the orbit for a period — I've forgotten, maybe two years — and it was published. Some months later somebody else published a refutation. He said that our results differ systematically from yours. They made the suggestion that perhaps we had used these tables of planetary effects erroneously. We went back into it and yes, I had. I had made a serious mistake. For the time period involved, using Jupiter, I would have to divide Jupiter's effect by 5. My teacher never told me that. Now to tie back into the original question.

Doel:

He had let you publish this?

Baldwin:

He did not. He published it under his name.

Doel:

I see. And this was someone on the faculty?

Baldwin:

He wasn't there very long. I am not going to name him but it was a beautiful object lesson in a good many directions.

Doel:

Do you remember conversations, in particular, in your undergraduate or graduate years with any of the people in the Astronomy department about the philosophy of doing science or how one goes about it? With whom did you feel closest?

Baldwin:

I was closest to Dean McLaughlin. We had a great many conversations but most of them were on interpretations rather than philosophical questions. I don't think that anybody was particularly effective in giving the philosophy of science. I have done a great deal of thinking about it in my own mind over the years and I think I have a pretty good sense of the field — what makes sense and what doesn't. Why things "are". But I think it is more from self-reflection, and reading.

Doel:

How much after hours socializing did you do with people like Dean McLaughlin and others?

Baldwin:

Very little.

Doel:

Was that simply how things were, by and large?

Baldwin:

No, that was done most of the time during the day when I was up at the observatory. The observatory is way at one end of the campus and I lived at the other end, about two or three miles away. That is a long way to walk, particularly when you have to walk back. We didn't go up there very often out of hours.

Doel:

Before we turn to your graduate years at Michigan you had mentioned that you had taken classes in geology. Are there any professors that you particularly recall? I was wondering generally what kind of courses you had in geology?

Baldwin:

They were just the elementary courses. We didn't have field trips. I guess the university didn't have enough money for field trips in times like that for beginning students. But I learned of the various eras that existed — the Cambrian era, pre-Cambrian, Mesozoic — all that type of thing and something about what they were. It was interesting enough to me so that I did outside reading. But geology is an evolving field. When I — let me jump ahead a little bit here — published The Face of the Moon in 1949, the age of the earth was thought to be 2 billion years. Now they are arguing about the third decimal place around 4.55 billion years.

Doel:

After doubling the accepted age.

Baldwin:

Yes. Nobody knew back there. Radioactivity was a relatively new science and people didn't know how much weight to put on it or really to do it in a laboratory to date rocks. We don't have rocks on the earth that go back to the beginning. I would say an awful lot of it was self-taught.

Doel:

We will get to that as we keep moving. One thing I was curious about, at Michigan, was did you have any contact with Arthur Adel?

Baldwin:

He was at Yerkes.

Doel:

But during the time you were in graduate school?

Baldwin:

Yes. Eventually I am going to mention a session at Yerkes which he attended.

Doel:

Do you remember anything particularly from the summer symposia? Were you in Michigan during the summers?

Baldwin:

No. Remember I was at Michigan during the Depression. I worked at the factory starting at 25 cents an hour and gradually, I think, I got up to 50 cents one year, to get money so that I could go back to school, to help in that.

Doel:

How did you come to your thesis research? Was it something that you had been thinking about?

Baldwin:

No. The University of Michigan observatory staff, each man had his own field. Dean McLaughlin was the world authority on the Be stars — stars with emission is what I mean — and I had thought that I would probably work in that field. But in 1934 there was a Nova Herculis and Mac got a lot of spectra of it and he got into that with both feet. They had, in 1920, gotten a series of spectrograms of Nova Cygni III but the features were so blurred — real blurry, not bad photographs but real blurry in the spectra — that nobody had taken that on as a thesis. Mac asked me if I would be willing to try it. I said sure. I did succeed in getting a reasonable interpretation of the evolution of that particular Nova and it was eventually published in the University of Michigan publications. The spectrograms had just lain there for 15 years. Nobody else was darn fool enough to do it, I guess.

Doel:

To reinterpret the spectrum?

Baldwin:

Yes.

Doel:

Was that actually your thesis?

Baldwin:

Yes.

Doel:

It was right afterwards in 1938 when your first papers began appearing in the Astrophysical Journal, that one of the first papers was about the forces of the system of Epsilon Aurigae. I was curious about that because it seems that you are dealing more with celestial mechanics.

Baldwin:

At the time of the first paper I was at the University of Pennsylvania — the Flower Observatory — and Otto Struve and Gerard Kuiper, and two or three others, published a paper about a very strange star, Epsilon Aurigae. They made a rather weird interpretation that the system was composed of a gigantic type F super giant star, and the largest star in the universe that they had found. But the latter was so faint it didn't emit anything but infrared light. Well, I read the article and didn't pay much attention to it and I came back a few weeks later and read it again. I said "That doesn't make sense." So I started to lay out the forces in that system because I didn't believe that infrared star could hold together. It showed that it just wasn't a possible solution so I drew out some charts on graph paper and wrote a few paragraphs and sent it off to the Astronomical Journal, who published it. I left the Flower Observatory, after one year. Charles P. Olivier was the director and he told me that "We've enjoyed having you here. I think it was worthwhile having you here and that Epsilon Aurigae thing was unique." I never got a response from anybody about it, but the Yerkes people never published anything more on it. It stopped it cold. About four or five years ago a man I never heard of was doing some more work on that star. He published a paper and he didn't know about mine. I sent him a photostat of it and he came back and said "I wished I had known about it — you certainly had something important to say about that star back in 1938."

Doel:

That is interesting. Had you already met Struve and Kuiper?

Baldwin:

Yes.

Doel:

Was that during the time when you were a graduate student at Michigan, or did that come later?

Baldwin:

That came — let's see now. I met Struve and Kuiper and a few of the others from Yerkes at meetings of the American Astronomical Society. It was just a "Hello, how are you" type of thing. I spent time later when I was at Northwestern going up to Yerkes to use their library which was better than ours and to talk to people.

Doel:

Let's get to that in just a moment. I am curious how this job came about at Flower Observatory? That was your first professional employment right after graduate school?

Baldwin:

Yes it was. I finished Ann Arbor in June of 1937 and I spent from June to August trying to find a job (or even before June) and that was right in the heart of the second part of the Depression where the bottom dropped out and somehow or other word came that there was a position at Flower Observatory for an assistant. Curtis read about it and sent a wire to Olivier and said "Baldwin accepts." Then he told me about it.

Doel:

That's remarkable. How did you feel about it?

Baldwin:

I was happy. It didn't pay very much. The salary for 10 months was $1,080 but the University had so much trouble meeting its payroll that they cut it down by... well, instead of getting $108 per month I got $102.57 each month from the University. I could live on that.

Doel:

There wasn't any university housing, though?

Baldwin:

No. I stayed at a house at 7830 Westchester Pike — almost up to the Flower Observatory.

Doel:

Who else was at the Observatory beside besides Olivier?

Baldwin:

A man named Taylor was there for a couple of years. There was one more man. He was, as I remember, doing double star work. I am not even sure if I can think of his name. All I really remember about him because I almost never saw him, is when he would come in and do his work he would whisper and talk to himself all the time he did it.

Doel:

Olivier was interested in meteor astronomy. Had you known much about his work before you went out there?

Baldwin:

No. He did not try to force it on anybody else but he did ask us to set up a program of research ourselves and I picked an eclipsing binary — TT Herculis. When we were making our observations he wanted us to record any time we saw a telescopic meteor. I saw three or four of them during that year — just little faint flashes. We recorded that in the log. But other than that we would give the course work that he wanted — laboratory works usually — and our own research. He did not have a formal program that anybody had to follow. Thank heaven!

Doel:

What sort of a man was he?

Baldwin:

He was a Virginian; a very charming individual. He was rather forceful, small (5' 9" at the most), and a rather nice looking man. He was an unreconstructed rebel. He still was fighting the Civil War and I once said something about slavery and the Civil War and he blew up. That wasn't the reason for the war! I always got along well with Olivier and I met him several times later.

Doel:

Did you have much interest in his research? Did you talk to him about it?

Baldwin:

I'd talk with him. I didn't have a great deal of interest in his work, but I would report back to him anything unusual on meteors that I saw. Some years later — maybe ten years — there was a scheduled meteor shower and as I remember it they were the Giacobinids. I had a beautiful view right off my front porch (the street light was out that night, too). I made counts in various intervals. We were getting sometimes 15 and 20 a minute, right on this little part of the sky.

Doel:

Per minute or per hour?

Baldwin:

Per minute! It was a rather big shower. As soon as it tapered off significantly I sent him a telegram giving these data. He told me later it was the first report he had on it. On one occasion there was a tremendous fireball which I did not see, but one of our foreman at the factory did see it. He took me over to where he was standing and he pointed out just where it had gone. I made angular estimates of what that was. Then, another fellow who had been with him and had seen it independently did the same thing and they matched beautifully. I sent that in to him and got a nice letter back. He helped Olivier in calculating their meteoroidal orbit.

Doel:

I gather then that you knew it was only going to be a ten month appointment at Flower Observatory and that you would need to be looking for another job?

Baldwin:

That is right.

Doel:

Did you have any other prospects at the time — any hopes that seemed to be developing?

Baldwin:

I was looking and Curtis sent me word that Oliver J. Lee of the Northwestern University Dearborn Observatory was looking for an instructor. I have forgotten now whether Curtis made the first contact or I did, but we both did. I took that position.

Doel:

That was as an instructor?

Baldwin:

That was as an instructor.

Doel:

What had you known about Northwestern before you had gone out there?

Baldwin:

I knew it was a private school. I knew that the school had a very fine reputation, that the observatory was relatively small.

Doel:

Had you had contact with Lee at all?

Baldwin:

No, not with Lee. Lee's predecessor was Philip Fox and I had met him and talked with him on various occasions before. I am not sure why now. It might have been at the Planetarium. He went there as Director after leaving Dearborn Observatory.

Doel:

At Chicago, the Adler Planetarium?

Baldwin:

He was director of Adler Planetarium after he left Northwestern.

Doel:

When you went to Northwestern, your discussions about what you would do were with Lee?

Baldwin:

Yes.

Doel:

How many others were in astronomy at Northwestern at that time?

Baldwin:

Lee had a man by the name of David Hamlin who was a millwright, a handyman around the observatory but he also observed. He was working on one of Lee's programs. There was a man named Dick Kinnaird. Dick was there for several years and he left to join Perkin-Elmer. I believe he finally retired from Perkins-Elmer. That was it.

Doel:

That was a very small department.

Baldwin:

It was.

Doel:

What sorts of research work were people doing?

Baldwin:

Frankly that was a very unfortunate situation. Lee — and I've got to be blunt — was not a qualified scientist. He got the idea that he could make a survey of the entire portion of the sky visible from Dearborn with a 10" objective prism instrument mounted on the 18" telescope. That was there when I came and they had been doing some work. We would take photographs on, if I remember correctly, 10" X 14" glass plates which would be bent in the holder to get them more nearly in focus throughout the entire plate. It did a good job on that. What he was trying to do was to identify stars and classify them according to the letter classification, as K, M, R, N and S stars. But then he went off-base and he decided that he could tell the difference between a giant star and a dwarf from the spectrum, particularly in the K's which were most abundant. There are practically no markings in the K spectrum that you could see. There were no big bands as there are in the M. He insisted that everybody on the staff observe, which is fine, and date these photographs and analyze them. He had a man by the name of Robert Torp-Smith — he was a Danish boy, about a senior I guess — build (with Hamlin) a photometer which allowed him to measure the brightness of the stars on the plates which were also taken just for that purpose with the same instrument but without the objective prism. He then could classify a star — let's arbitrarily say a K-6 dwarf of magnitude 9.2 —

Doel:

Was his goal, in a sense, to cover as many stars as possible to make this type of observation?

Baldwin:

This was a long-term operation. He wanted to cover as much of the sky as possible and to catalog these types of stars. There were hundreds of thousands of stars. Everybody else there knew he was getting data that were not good but you couldn't convince him of it. On one occasion Dave and I took the Harvard catalog that Annie Cannon had developed and identified, in her catalog, as many stars as we could from our catalog and I got, I would guess, 1,000 or 2,000 stars. I plotted her spectral classes against what we were saying they were and in the R, N, and S we were all right. In the M's we weren't too bad but when you got into the K's it was just almost a scatter diagram. I took it to Lee with Dave. Lee was ready to leave on vacation, and he took it very well. We thought, boy we had made progress! He came back from vacation and he lambasted us to hell and high water that we were making a personal attack on him. I had to finish out that year and I might have stayed longer, I don't know, I hadn't come to any conclusion then. But World War II interfered.

Doel:

This is early 1940-41 that you are talking about?

Baldwin:

Yes. Of course, this had gone on for quite some time. Lee permitted us to do other things if it didn't interfere with his program. He very quickly, after he got back and he had vented his anger at Dave and me, started to publish what we had all collected but he limited it to the M, N, R and S stars. I could show you, I have one of the publications here. That I think is fine and we did discover a large number of N and R stars that were not known before.

Doel:

Would you say the atmosphere in the department at Northwestern was unhappy because of Lee's presence? Was he a domineering figure?

Baldwin:

Lee was almost a megalomaniac. The atmosphere was not right. Kinnaird left right in the middle of a school year. I made arrangements to leave and I pulled Hamlin with me later. I'll go into that later on. I can give you this illustration. My blood pressure is normally about 128/70. It has been that way for many years. I had it taken once while I was at Dearborn Observatory, that I remember, and it was up to 200. It probably is right now, too!

Doel:

Did you have much contact with the Physics department at Northwestern?

Baldwin:

Only one man, though I met many of them — Russell Fisher I knew well. We would go out with him in the evening occasionally.

Doel:

What was the mechanical condition of the instrument capacity of the 18 1/2" of Dearborn Observatory? Would you say it had been brought up to as near to state of the art as you would like or were there difficulties?

Baldwin:

I think it was in excellent condition. Basically, it was maintained. Dave did a good job on that but it was basically ordinary clock control with a governor and so on. It did not have the computer controls obviously that we would expect now. It was a very fine instrument. I have never told this story publicly but I am going to. I nearly broke it once. I got up on the inclined seat and unclamped the telescope but it jerked out of my hands and started to swing down so that the lens end would come down and hit the column. Well, I jumped for the floor and got between the column and caught the lens end as it came in. I never told Lee or anybody else but I checked and Lee had been working on it before, and he had taken some weights off to do something with the objective prism — I don't know what — and the weights were off and the telescope was unbalanced and started down. I still get goose bumps thinking of that. But I wasn't going to tell him what he did. I put the weights back on.

Doel:

I suspect that is probably a more common story among astronomers than is generally known.

Baldwin:

I imagine so.

Doel:

Did you have any contacts with the geology department at all during this time?

Baldwin:

No. You see, while I was at Northwestern I had not started my work on the Moon until the very end.

Doel:

I am curious about how that came about.

Baldwin:

Are you ready for that? Lois and I were married August 1940 and in September of 1941 our son Dana was born. Instructors weren't paid very much in those days. We got along and we saved money but it was hard to do it. So, I took a job at the Adler Planetarium lecturing at so much per lecture. I would go down on the first Sunday of the month, listen to the first program, and give the second one. You gave the same talk for one month. I usually gave about 20 in a month. The planetarium is a marvelous instrument for speaking, too. If you fall asleep because you've been given the thing 15 times before you can look up and say "Here I am" and go on. Besides you are in the dark and nobody can see you blush if you make a mistake. I enjoyed it. It was a very pleasant thing but it is about 16 miles down to the planetarium from the Dearborn Observatory and I would drive down there on the Outer Drive. I never knew what the traffic would be so I would have to drive down early. Then people were working there and they didn't want to talk, particularly, every day to the same fellow. I would spend some time wandering around the corridor which surrounds the planetarium chamber.

Doel:

Were the exhibits in there?

Baldwin:

They have exhibits all around. They were 18 X 24, most of them transparencies, lighted from behind. Four or five of them were of the Moon. There was the famous 1919 Mt. Wilson picture.

Doel:

Photographs?

Baldwin:

These are photographs.
Doel: The Pease photograph?

Baldwin:

Yes. There were some from Pease but the best ones — except for the Mt. Wilson picture — were from Lick. I wasn't particularly interested in the Moon but I began to see a few features on the Moon that just didn't make sense. I couldn't explain them. They were elongated valleys, usually with raised sides. The closer they were to Mare Imbrium the wider they were relative to the length. When we got out as far as the Ptolemaus region they were long grooves. I tried to look up in the literature that we had at the observatory to see if anybody else had noticed them. A few people had drawn them on maps but never a comment. I finally found a paper by a man named Steavenson, from England. He had published about 1919 the idea that maybe those valleys in the Ptolemaus area had been formed by the almost tangential impacts of a swarm of giant meteorites. That didn't make sense because some of them were not parallel to the others. About 5 feet behind you in the next room is the photograph from Lick Observatory on which I drew the positions of these various valleys and then projected great circles through them. They intersected not at a point but in an area in the center of Mare Imbrium. When I saw that I began to get excited. Something big had happened in Imbrium. I woke up to the fact that that was a giant crater — 1200 km across — and an explosion had occurred there of almost inconceivable violence, ejecting material, and that flying material had gouged out these valleys. I didn't see how they could do it physically but the evidence was there. I went to Lee and told him that I thought I had discovered something on the Moon that other people had not seen. And, I was shocked — he pooh-poohed it!

Doel:

Did he give a reason?

Baldwin:

Yes. He said it doesn't tie in with the program of the observatory. Well about a week later I woke up to the fact that he didn't say I couldn't work on that. He just said it didn't tie in. So, I started work. Sometime later — a month maybe — I had done a good deal of work. I had gone through every book that we had at the observatory and tried to find everything I could about the Moon. There wasn't a heck of a lot of it.

Doel:

Do you remember particular articles that you had read — which ones you had come across that impressed you in particular?

Baldwin:

I can go back to The Face of the Moon and look in the bibliography and name them, but not off-hand. The reason I say that is because I can't place them in time. About three weeks or a month later, Lee and Kinnaird and I went to Yerkes to a symposium up there. While there I was talking to Otto Struve and told him that I thought I had found something very unusual on the Moon. He said "You are giving the next symposium." I gulped — here I was barely out of school and they had world-famous astronomers up there: Struve, Kuiper, W. W. Morgan, Phil Keenan, Arthur Adel and I don't know who all else — Al Hiltner, van Biesbroeck. I went back and prepared some slides and prepared this talk for them and came up a month or so later, and gave the talk.

Doel:

And this is now around —

Baldwin:

This is in 1941. Let me get it straight. Yes, it was towards the end of 1941. Pearl Harbor had not yet occurred. But what absolutely shocked me was that here I had been working for a couple of months on a portion of the Moon and reading about its history and what we knew about it, and I knew more about the Moon than any of those world-famous astronomers! The Moon was subject anathema. It just got in the way, as I mentioned earlier. I had changed my opinion but nobody else had. Well, I presented the paper and offered it to the Astrophysical Journal and it was turned down.

Doel:

What was the reaction at the colloquium when you presented that idea?

Baldwin:

Everybody seemed to feel that "Yes, you have found evidence of a gigantic explosion in Mare Imbrium but that doesn't prove that the rest of the craters were impact."

Doel:

Is that so? The prevailing opinion felt at Yerkes was that....

Baldwin:

Most of the craters were volcanic. They didn't try to say what produced them. I did. I said it was giant impacts. But most of them were convinced (if convinced is the right word) that the major round features on the Moon were volcanic.

Doel:

That is quite interesting. Do you remember anyone in particular who made that comment?

Baldwin:

Phil Keenan made that comment specifically.

Doel:

Did Struve or Kuiper seem to agree with that?

Baldwin:

Kuiper had not done any work on the Moon at that time. I don't remember him saying anything personally about it but the general reaction was "It's a most interesting paper and something big happened in Mare Imbrium (we didn't call it the Imbrium Basin until much later) and I hadn't proved the case for the ordinary craters." Well then, as I said, I did offer a paper that I wrote after this symposium to the Astrophysical Journal of which Struve was editor — and he turned it down. It didn't fit.

Doel:

Did he give you a reason?

Baldwin:

Well, it really wasn't an astrophysical problem. Then I went to the Astronomical Journal and they didn't give me any reason at all. They just turned it down. Lee wouldn't publish it in the Annals of the Dearborn Observatory.

Doel:

Again feeling it wasn't in the program that he was working on?

Baldwin:

I am not sure whether he felt that or whether he felt that I was nuts because after all, the Moon had been up there for a long, long time. Great astronomers of the past had decided that these were volcanoes and here was an upstart coming along saying they were full of the juice of little red ants. You don't make changes like that. Well, I finally got the magazine Popular Astronomy to take it and to take the second one which followed. They were published actually in 1942 and 1943. Those, in effect, were my introduction to my study of the Moon and when I realized — after this talk at Yerkes — that astronomers didn't know and didn't care about the Moon and that there were things to be found about it, I said to myself "Here is a field that nobody else is going to mine — so I should do it."

Doel:

Do you remember or writing and corresponding or talking with other astronomers or even other geologists at that time about the articles? Did you have contact, for example, with Henry Norris Russell?

Baldwin:

No. The last time I talked to Henry Norris Russell was about my thesis on Nova Cygni. I did write to him about the moon — this was during the War — and he wrote back "It is most interesting but I hope you will put your efforts in winning the war."

Doel:

I imagine that seemed to be another slap of sorts against that kind of research?

Baldwin:

I felt it was but Russell was too great a man to state an opinion at that time. I felt he was sincere, really, in saying the war was the big effort and it must be, and it was.

Doel:

Were you aware at that time that Russell was a member of the committee that John Merriam had appointed at the Carnegie to investigate the surface features of the Moon?

Baldwin:

No.

Doel:

Had you been aware at all about that committee?

Baldwin:

I don't know anything about it.

Doel:

It began in the 1920s. It was at that time Russell became convinced that the craters had to have been formed by volcanoes. He seemed to be persuaded by their arguments.

Baldwin:

In fact, I to this day do not know anything about that committee.

Doel:

We might talk about that later. A number of people were involved including John Buwalda, the Caltech geologist.

Baldwin:

The only geologist who, prior to my work, backed the impact theory more than casually was G. K. Gilbert.

Doel:

One other thing I did want to ask you is once the articles had appeared in Popular Astronomy did you get reactions from any astronomers or geologists who had read them?

Baldwin:

A little but not a great deal. Roy K. Marshall, who is a Michigan graduate and a planetarium lecturer — he never really did much in publishing — developed a theory of the origin of the lunar craters, that they were formed by laccoliths and a falling in of the center. I visited with him on three or four occasions (at meetings) and his general reaction was, he said, "Baldwin you are absolutely wrong." I am going to quote him now. "Your mode of formation of these giant craters intuitively is impossible." That was his reaction. He couldn't see the big picture. It was outside of his realm of experience and therefore it wasn't so. I had people writing — Escher from Italy and Miyamoto from Japan and some from the United States that I would see personally but not write — who just plain couldn't accept the impact theory.

Doel:

So most of the responses you got were criticisms of the impact theory?

Baldwin:

A man named Spurr wrote four books on the general subject of geology applied to selenology and stated specifically that he saw no evidence of impact cratering. Well, he was honest and sincere, and wrong.

Doel:

The Miyamoto that you mentioned in Tokyo, he was the astronomer who a number of years earlier had worked on asteroid development?

Baldwin:

I believe so. It was not Hirayama.

Doel:

Do you have a sense for the main reasons astronomers felt uncomfortable with the impact hypothesis? Was it the energies involved or was it other questions involving the solar system that seemed to jar with their conceptions?

Baldwin:

I have to make a guess. I will make two or three guesses here. In the first place, everything up to and including, the 1908 Siberian Tunguska Impact were small bodies. Nothing large was falling on the earth. Nothing large had fallen on the earth in geologic history which would produce a giant crater as far as they knew. If it didn't happen to the earth, it didn't happen to the Moon. I think that was one of the biggest drawbacks. Certain well-recognized astronomers — like Nasmith and Carpenter, Beer and Mädler, had studied the Moon through small telescopes and had pronounced these things volcanic. The Moon was not of interest to most astronomers and consequently an authority has said it was volcanic and I have no reason to disbelieve them — I haven't studied it — so I accept it. I think that was the general attitude of most astronomers. There were some exceptions. Whipple, Millman in Canada, Watson at Harvard —

Doel:

All, in fact, were at Harvard at one time.

Baldwin:

Yes, every one of them was. Those people said the meteoritic theory of impact cratering on the Moon is probably correct and then they cut it off there. They didn't do any more work on it.

Doel:

Do you recall this in the 1940s right after the Popular Astronomy articles, or was this a later discussion?

Baldwin:

I think it was a later discussion. I have talked these things over, particularly with Whipple and Millman, and Millman has reviewed my The Measure of the Moon and he says "Yes, we did think about those things and we thought the impact cratering theory was probably correct or was correct, but we didn't take the time to study it."

Doel:

Of course, Watson was a major promoter of the idea.

Baldwin:

Yes, he was. He wrote his book in that Harvard series which discusses it. But talking about it had been done for a century. Gruithuisen in 1829 published it. Nobody followed through. Proctor in about 1873 advanced that theory. He later withdrew it. I think the main problem was that the Moon simply was too close to us to be an interesting subject of study.

Doel:

Of course, it also involves different realms — one doesn't treat it with the same techniques as one would stellar objects. One last question before we do talk about your APL period. During the Second World War, I believe you attended the Neighborhood meetings of astronomers?

Baldwin:

Yes.

Doel:

Can you tell me a little bit about how often those were, and any memorable experiences that you had?

Baldwin:

Well the AAS met once a year all over the country. I attended one at Williams College, one at Ann Arbor, one at Radcliffe; then when the war came along I did not, except for the Williams College one, go to such meetings. Yerkes would have meetings on a monthly basis and I attended maybe half of them. We never had that kind of a meeting at Dearborn. It was too small. Ann Arbor would have an occasional meeting and I went over there a few times. That is about it.

Doel:

What was the format? Would someone present a particular topic?

Baldwin:

Everybody talked, every time. One person presented a paper and then there was a discussion sometimes and sometimes not.

Doel:

Let me just ask you this as well. Was it in the early 1940s that you met your wife, Lois? She was at Northwestern during your time of instruction.

Baldwin:

I met Lois in December 1939. We were married the following August. There was a church in Evanston — a Methodist church — and it had a Sunday evening club that was called the PKK, which meant post college club. People of all denominations and all colleges in the area — there were usually several hundred — came on Sunday nights to that meeting. They would have a program and for some reason or another, Lois and a friend of hers decided to come to a meeting one day. That was her mistake!

Doel:

You had really just gotten settled, as you tell in your book on the Fuze project, in Evanston at the time you were recruited to the APL. Was that by Robert B. Roberts?

Baldwin:

No. It was by Robley Williams. We had started a house in Skokie, about three miles from the observatory, and they broke ground on the 6th of November 1941. Then a month later Pearl Harbor and the government put all sorts of restrictions on. If you didn't have the foundation in you couldn't proceed. If you didn't have the roof on you couldn't proceed, and so on. To this day I think that Charlie Minter, our contractor, had a pipeline to Washington. He knew what was going to happen because he apparently arranged things so that he was a day or two, or a week ahead on every one of those things. We finished the house in March and moved in, and moved out in late May and never went back. I had trouble finding that house several years ago. We had ten miles of open land out our kitchen window. It is built solid now.

Doel:

Could you say a little bit about what role Robley Williams played in getting you to APL?

Baldwin:

Well Robley had been on my doctoral committee and —

Doel:

Hadn't McLaughlin been the director?

Baldwin:

No. Not director — he was my chairman. He wasn't the director of the observatory.

Doel:

Your thesis committee?

Baldwin:

Yes. I had lost track of Robley and didn't know he had gone to Washington and was one of the early employees at the Department of Terrestrial Magnetism of a committee under the NDRC. When it became evident that the proximity fuze was going to be the project that this group, under Merle Tuve who was then the scientific director of DTM, that was going to be their project. The various members — Tuve, Larry Hafstad, Richard Roberts, Robley Williams and a few others — were each given a section of the country to contact for people who might fit into that program. I was in talking one day in March — in Dr. Lee's office talking to him — when the telephone rang. It was right behind his chair. And he answered it and handed me the phone. It was Robley Williams. He wanted me to come to Washington. I said "What for?" and he said "We have a project that you might be interested in, that you could help with. It has to do with the war." I said "What is it?" and he said "None of your business. We want you down here as quickly as you can for an interview if you have any interest in this." I turned to Lee and Lee was in his mad period. I think he was very happy to get rid of me. He said "Oh Ralph, you have to accept." So I made arrangements over the phone to fly down to Washington and meet with Robley and whoever from the laboratory he wanted. He met me at the plane and we went to the Department of Terrestrial Magnetism — didn't even go in. We stayed outside; it was a beautiful day in the spring — and talked. He had E. D. McAlister and Ed was to be my boss during the entire war period. He was a great man. I never went through an interview like that before in my life. It wasn't an interview. We just sat and talked. Robley made his abominable puns.
[Break]

Doel:

We're resuming after a break for lunch. You were talking about Ed McAlister. I wonder if you had more you wanted to add about your relationship with him?

Baldwin:

Ed was a physicist. I am not at all sure what work he did before the war but apparently was quite well known. He was one of the most cheerful individuals I ever knew. He was a driver. He drove himself hard and he expected his crew to work equally hard. He was in charge of what is called the service group at the laboratory — Johns Hopkins Applied Physics Laboratory — and he was in charge of the relationship between the U.S. Navy, the laboratory, and the British working primarily through E. O. Salant. I was working under McAlister, in charge of contacts with the United States Army. Bob Herman (Dr. Robert C. Herman) was in charge of relationships with the United States Navy throughout the war. We all had different jobs at different times but those were continuous. Ed died about two years ago. He developed a brain tumor but he passed away peacefully. His sons kept me informed. He was living out in Oregon. When he was a very young man I know he was a timber topper, working with one of the big lumber companies and going up to the top of the big pine trees before the branches were cut off and the tree cut down. You could see he was a good physical specimen throughout all of his life. I had a great liking and a great deal of respect for Ed; or as we usually called him, Mac.

Doel:

You have written quite a bit about the Fuze project in your book. It's probably better that we not spend too much time just on that part. I was curious if you had anything that you wanted to add that was not in the book — that you wanted to have placed on the record?

Baldwin:

I have not come across anything of consequence that was published after the book came out, so I think I would have to say "no" on that because in writing the book I got all the help that I could get from many of the people who had worked at the laboratory. Of course, many of them had already died. Fortunately Merle Tuve was still alive and although he had heart problems, he did contribute very substantially. I had great cooperation from Bill Buchanan, particularly, at the Applied Physics Laboratory and on one occasion we held a get-together of the people who had worked on the laboratory and of some who had worked in the companies working for the laboratory, reminiscing. That was after the book came out, however, but even then very little new was added. I think I have pretty well gone through the available material. There was one more thing. A professor in Scotland by the name of R. V. Jones during World War II was sort of a right-hand man for Winston Churchill and he was in charge of anti-radar and radar matters — radar intelligence — for Churchill. He has written substantially on that subject and he and I have corresponded now for about three years and he did dig out a little more information on the early history of the proximity fuze in England which I would use were this book ever to be revised.

Doel:

What was your relationship with Merle Tuve?

Baldwin:

It was a love-hate reaction which we all had and I think I was scared stiff of him. Merle was probably the most dynamic man I ever met. He was as smart a man as I ever met. He could see through the essence of a problem to the core without fail. He drove us — that is why I said "hate," but love and hate are very closely related — unmercifully during the war because we had to get the project done in time to be of use during World War II. I have as much respect and liking for Merle Tuve as any man I have ever met.

Doel:

How did the other people at the lab perceive him?

Baldwin:

I think it was just exactly the same way. They knew he was a great man. He should have won the Nobel Prize for some of his work on reflecting regions in the atmosphere of the Earth. But, that didn't come about. We all knew he was top grade.

Doel:

Let's turn to your general responsibilities within Section T for the moment. You were, if I am not mistaken, generally in charge of army matters within this section?

Baldwin:

That is correct.

Doel:

What did that involve?

Baldwin:

I was working with my opposite number, Col. Harold S. Morton of the army and Morton was in direct contact with people as high as George C. Marshall — General Marshall — and as low as the lowest man who had anything to do with the fuze. He was a generalist — a brilliant man. He and I would meet regularly to discuss the progress that was being made so that he could transfer it back to his superiors in the army. On one occasion I was driving to the Army War College to meet with a Col. Furuholman. His name was Bjarne but we, of course, called him Barney. On that particular occasion the thought occurred to me that we had always been aiming the proximity fuze as a defensive weapon against aircraft but that the fuze would operate by influence of almost any target. Consequently it should burst above ground. We had been testing it above water. It should burst above ground and if so, it would give us a tremendous weapon because air bursts are very much more effective than ground bursts of shells. I got thinking about that on the way down to the war college on this day. We got there and I opened my mouth to tell him and Barney said "Ralph, I think there is another use for this fuze." We immediately began to discuss our mutual thoughts. I went back to the laboratory, contacted Dr. Philip Rudnick and told him what we were after, and Phil modified some circuits and we had some fuzes built. They were too big to use in the ultimate howitzer weapons that we would be talking about but they could be tested in the 90 mm gun. We did test it with these fuzes and they worked. We went back to the Army War College, discussed the matter and on their recommendation we ran a whole series of tests on safety devices and the operability of fuzes and so on, in the 155 mm Howitzer. The date of that first test was April 29, 1943. On July 9 we demonstrated with ten rounds of 8" howitzer fuzes before army representatives, including Col. Malcolm R. Cox and Barney Furuholman, and nine out of the ten operated above water at a forty-second flight time, which seemed like an absolute miracle to Cox. As a result of that test, the army placed an order for a million fuzes at $75.00 a fuze. We ultimately got the cost down to about $18.00/fuze but that program multiplied the anti-aircraft portion of our original program by a factor of ten. We ultimately built 22 million fuzes.

Doel:

You mentioned your counterpart in the army, Morton. What kind of background did he have?

Baldwin:

He was an engineer but I think he had been with the army engineers. I am not sure. He had been a major in the army when I first knew him. He had been with the army for a considerable period of time before the war.

Doel:

It became clear, as the war grew to an end, that the future mission of the APL was in question and it was in January of 1945 that APL had begun introducing the Bumblebee Project. I am wondering what kind of involvement you had in those discussions? Do you recall discussions about the future of APL?

Baldwin:

Well, unless you were one of the top two or three, you did not really get involved and did not want to get involved with other projects.

Doel:

You are speaking of the senior committee?

Baldwin:

The very senior group.

Doel:

And you were a member of the —?

Baldwin:

I was down about three layers. During the war, we started with the proximity fuze work and brought that to a successful conclusion although evolution continued throughout the entire war. Then as the use of the fuze continued in the fleet it became evident that the Mark 37 — I believe it was — gun director was a very poor one for use in anti-aircraft. It really was designed for ship-to-ship or ship-to-shore bombardments. It controlled all of the guns. Each gun or each double twin turret needed its own director. The Mark 57 was assigned to the laboratory to develop and they did develop it and got them into the fleet in time to be of major use as the fleet moved westward in the Pacific. There were other projects like Ramjets and so on, which the laboratory got into but since they didn't particularly affect us we didn't make any effort to find out what they were doing. The laboratory expanded — new people came in but they were working really in the compartmentalized fashion.

Doel:

So you really didn't have much information about what was going on?

Baldwin:

I knew a considerable amount about the Mark 57 gun director. That was the first of them but in later projects, no, I did not know.

Doel:

Do you recall meetings in early 1945 at which you participated in discussions about the future of the laboratory with other members of the young Turks?

Baldwin:

Not just of the young Turks but there were what we used to call policy meetings, which were held. As the war drew to a close there were a considerable number of meetings that were attended, for example, by our staff and then Rear Admiral now Vice Admiral George Hussey, and by the man who later became the Chief of Staff, Admiral Arleigh Burke who was called "Thirty-One Knot Burke" when he was heading a destroyer squadron in the Pacific; Representatives of some of the companies like Eastman Kodak. They tried to find what the proper function should be. The original thought was that we'll close it up just as the Radiation Lab closed up right after the war. The services in general said "no" that it shouldn't be closed up because there were many more projects that should be studied by a qualified group. Some of us were asked to leave at the end of the war. I was asked to stay but chose not to. Some very good men remained and the laboratory stayed for a while at 8621 Georgia Avenue in Silver Spring but then later was moved out into Howard County to its present location and new buildings were built. It is still in existence and it is doing military research some of which is tied in with medical research. Companies like Eastman Kodak took on the development of the Proximity Fuze and they improved it tremendously. They have increased the shelf life of the fuze and increased its performance and its accuracy. Well, even with much of guided missiles today nowadays there are still places where the Proximity Fuze would be of service.

Doel:

Were you not for a time involved in the upper of the high altitude research group?

Baldwin:

No. That was under Clyde Holliday. He got involved in that group who had some captured German V-2 rockets. Clyde had married one of the girls who worked at the laboratory. We knew them and he, on occasion, showed me some of the photographs that had been taken from 100 or 50 miles up from these test rockets, which ultimately led to the Voyager II that just completed its pass by Neptune.

Doel:

Do you recall having discussions with James Van Allen about the future of the APL? How well did you know him?

Baldwin:

Jim and I occasionally had adjacent desks but usually were in adjacent offices. We worked together throughout the war. He was more involved in the U.S. Navy phases of the Proximity Fuze work than I was. He came a little earlier to the lab. He developed radio sondes, for example, in which you could measure the rotation speed of the projectile which was critical to the development of safety features in the fuze. Later on, after the fuze was introduced, Jim and two others from the laboratory — Neal Dilley and a man named Peterson — were commissioned lieutenants as I remember and were sent out to work with the fleet to introduce the fuze, to handle problems that developed, and train people in how to use it.

Doel:

Can you tell me why you feel you were asked to stay on at APL? What was it that those who made that recommendation had in mind for you?

Baldwin:

It was easy to get followers. They wanted leaders. I think during the war I had demonstrated this particularly with the pushing of the anti-personal fuzes for the U.S. Army and the British army, pushing that through to a successful conclusion. I was not on the research end of that. I didn't say you should have this circuit or that circuit. But I was instrumental in starting it and seeing that it continued successfully and to field test them; to develop specifications for performance, to train some of the field artillery people. In fact, we were at Fort Sill, Oklahoma, a Captain Robert Klopfenstein — who was Col. Morton's right-hand man — and I, we were at Ft. Sill training field artillery people from every theater of the war when the Battle of the Bulge started. We just finished in time on that one.

Doel:

Did you have an interest at that time in upper air research, given that that was one of the clear directions the laboratory was moving after the war?

Baldwin:

Not upper air research, no. I was very interested in the Moon. I was writing the beginning phases of The Face of the Moon at the end of the war and to a limited extent I was interested in stellar spectroscopy, but I didn't have the equipment available. I could have gone back into academia or gone back to Northwestern, or perhaps some other place but it just seemed that I was needed more in the family business.

Doel:

I do want to talk with you about that in just a moment about that decision. But when exactly did you leave APL? How long were you connected to them?

Baldwin:

The war ended in August of 1945. I think it must have been the following January when I left APL but I took a year’s contract to act as a consultant on specified specific projects which they would furnish me. In my home in East Grand Rapids, Michigan I set up an office which met security requirements — safe and so on — in my basement. I did work for the lab for a year.

Doel:

Was that when you were working on flight characteristics or was that not an area of responsibility that you had?

Baldwin:

I didn't do anything on flight characteristics. I worked on sound patterns around airplanes with the idea that maybe a different kind of proximity fuze could be developed, and on several other special projects which they would assign me.

Doel:

Were these projects more or less connected with your previous work on the Proximity Fuze?

Baldwin:

It was an outgrowth of that work although it did tie in also with the fuzing of some of the early guided missiles.

Doel:

Did you have extended contacts with other people who were involved in those projects. As you know, the connection with Rudolph Ladenberg and Mira Nickels from Princeton —

Baldwin:

No. I had no contact with anybody except the people at the laboratory and almost all of my contacts at that time went through Robert Thayer, who had been head of research for the laboratory during the war.

Doel:

Does anything stand out in that contract year?

Baldwin:

You mean as far as applications and results?

Doel:

Anything, generally.

Baldwin:

I would have to say "no" because I never heard anything more about them. The results went back in and they fell into a hole maybe or somebody used them. I don't know.

Doel:

So you felt distant during that time?

Baldwin:

Yes. It was a short term thing and intended to be. It was a one year contract.

Doel:

You also had contacts with industry, such as with Aerojet and Douglas. Was that also an outgrowth of the Proximity Fuze or did that come later?

Baldwin:

No. That was entirely connected with the Moon program.

Doel:

Ok. We'll get back to that then a little later on. Did you remain at APL or have enough contacts with APL for the opinions of the people that you knew well at the lab for Van Allen's work — the post-war work that he was developing?

Baldwin:

I didn't have direct feedback from that. Jim did excellent work during the war. He was a very valuable man at the laboratory and we were very proud and happy to have him. He was a young fellow, of course, and didn't give any great forewarning of some of the things that he would do afterward. He became head of the physics department at the University of Iowa. I don't know whether he went directly to Iowa from the lab or not. He has retired from that. Of course everybody knows of his discovery on our first satellite of the Van Allen belts, which made him a world-famous man.

Doel:

When you left APL in January of 1946 for the one year consultancy you mentioned that you had decided that it was better and proper for you to go back into business. I am wondering if you were weighing the possibility strongly of going back to Northwestern or whether you had other offers or if you considered even at one point staying?

Baldwin:

I didn't put my name out at all because even though I was on leave from Northwestern for the duration and could have gone back there, really my first contact with them as the program wound down was to tell them that I was not coming back. My reason for going into business is that our family, our company Oliver Machinery Company, was owned by two families. My father and his younger brother were from our side and there were two generations of the Tuthill family on the other. The elder Tuthill was one of the first employees of the company and his son, who would become president when my father retired in 1955, and his brother in 1956. Dad and Uncle Ralph began to realize that "Here Howard was coming in and he had two sons and we have nobody following and sooner or later the entire management of the company would be in the hands of the other family." So, they contacted me and asked me if I would come which I did. I have never regretted it. Really I have had three careers: astronomy, which has gone on both professionally and privately for 50 years, the military research, and the manufacturing. And, if I have learned one thing about this, a man can throw himself wholeheartedly into any field of work and if he has any abilities he can in effect fall in love with it and find that's a very important thing he is doing. I have done that three different times. I have no regrets over not staying in the field. In fact, I had the best of all worlds. I was in management in a company which was a very challenging matter and I could continue in certain phases of my astronomical work because it didn't require an observatory. I could, in effect, apply myself where my interests were.

Doel:

Lunar studies?

Baldwin:

Yes.

Doel:

Did you have at least some time to do research when you had gone to Oliver, or was time very limited?

Baldwin:

I did not stint the time that I put in at Oliver. But that is eight hours per day and there are sixteen other hours. As my wife put it once when a man said "How did you ever do it?" She said, "He moonlighted." I did. In fact, since I was working on the edges of what was known a lot of my work didn't involve pushing a pencil or reading. It was just thinking — thinking over the relationships and so on. Quite often when I would go to bed at night I would just lie there for an hour or two hours, just mulling things over in my mind. It didn't interfere that way with the work at the company.

Doel:

During those first years when you came back from the APL did you have contact with any other astronomers — strong contacts either at Michigan, or any remaining contacts with people? Did you have a chance to discuss this work with anybody else?

Baldwin:

It was done more by letter than anything else. The Face of the Moon was being worked on in the last year of the war to a limited extent. I didn't complete it until the beginning of 1948 or end of 1947. It was accepted by the University of Chicago Press and I wanted the earliest possible date on it. They wanted next year's date on it. So, they held up publication for a couple of months and put it into January 1949. In that period of four years (3 1/2) after the war I had basically the information I needed. I kept up with new publications and I wrote a substantial number of letters to people, like Whipple, Watson, Millman and so on. I incorporated everything that I could.

Doel:

Are there particularly any contributions that those members or ex-officio Harvard members gave you?

Baldwin:

No. It was mostly encouragement. I can give you one example, a little different. One man I had been corresponding with off and on was an old (80) geologist, also from Harvard. His name will come back to me: Reginald Daly. One day in 1948 I got a letter from him. He asked me, "Do you by any chance have reprints of your two articles in Popular Astronomy discussing the events on the Moon? If so, please send them to me. I should treasure them." I did and I sent him those two. He closed his letter to me saying "Your work bears certain resemblances to that of G. K. Gilbert." He gave me the reference which is the first time that I had heard of Gilbert. I had time to get a paragraph put into the book outlining what I have just told you and recognize Gilbert's work. Gilbert had made one fundamental mistake. His paper was the paper of the retiring president of the Philosophical Society of Washington and it was published in their annual publication. A few older people maybe heard it or had picked it up but it was almost completely unknown. Now everybody knows it. It is a very famous paper. An interesting thing about it is that I was working on The Face of the Moon. Gilbert's paper was called "The Moon's Face."

Doel:

That is interesting. Did you have any other contacts with Daly?

Baldwin:

No, he died shortly thereafter.

Doel:

Was any of the research that you were doing with the Proximity Fuze and seeing shell burst and soil helpful in developing the ideas for The Face of the Moon?

Baldwin:

Not fuzes that worked, but there was a substantial amount of information to be gathered from the army sources and from seeing data on bomb and shell craters. I collected a huge amount of information on them available for use later on. They were of great help.

Doel:

One of the main concerns — lack of information at the time — was knowing the relationship between the energy produced by an impacting object, and how one scales up to greater energies and sizes.

Baldwin:

Nobody — I shouldn't say it that way because I am not sure — but it was not general knowledge that the size and shape of a crater varied tremendously for a given explosive charge on where that was exploded, how far below ground level. The shape of the crater is very similar for a wide range of depths but the size of it as the burst goes down; the size of the crater gets bigger and bigger and bigger for the same explosive charge to a maximum. Then it begins to get smaller and finally it ends up as what they call a camouflet — a hole in the ground well down and no crater. Our early estimates on the amount of energy needed to produce impact craters, such as the Arizona crater, were way off base because we had used craters produced by military mines, I had and I believe C. C. Wylie of Iowa had done the same thing, because we got similar results for the Arizona crater; results that were off by a factor of about 100 in energy.

Doel:

When was this that you were doing the work on the calculations for meteor crater?

Baldwin:

That was prior to the publication of The Face of the Moon because I quoted it in The Face of the Moon. A man named Lampson published around that same time a book on explosive craters in which he said that the size of the crater for a given scaled depth of burst varied as the inverse cube of the energy — of the ratio of the energies. He was close to it. It now appears that it is not 1 over 3 but 1 over 3.2 to 1 over 3.4, depending upon the size — the amount of the energy. Between the time The Face of the Moon came out — I didn't know anything about scaled depth of bursts then — and The Measure of the Moon in 1963, I had seen the light and made some major corrections and changed the energy from something times 10 to the 21st ergs to about 3.4 times 10 to the 23rd in the other for the Arizona crater. It might be interesting at this point to point out that I had applied similar reasoning on the Tunguska explosion in 1908. [Added later by Baldwin: I was the first to state that it had to be an airburst. The body never hit the earth]. A man named Sekanini much later published something on that in Science and then in Sky and Telescope. I told him about some of my earlier work in a letter and he came back and said he didn't know about it but he had gotten the books out and read it immediately. He said "It is interesting to me that way back that far, your value for the energy derived in two different ways; brackets the best estimates of today." That pleased me very much.

Doel:

Did you have much contact with Wylie at that time?

Baldwin:

I had one letter I think it was, exchanged between us. It wasn't until later that I realized that we were both wrong in the amount of energy in the Arizona crater. I tried to contact him again, but he was ill and couldn't be reached. I tried later on and he had died.

Doel:

Had you met him personally?

Baldwin:

No, never met him.

Doel:

But you were generally aware of the research he had done?

Baldwin:

Oh yes, I had his paper. There were darn few papers that were available that I hadn't seen at that time because as I told you at lunch (not on this tape) I had made a book by book search through the Naval Observatory Library helped by Mrs. Savage and also the U.S. Geological Survey Library.

Doel:

At the Geological Survey Library did you hear anything about the Gilbert piece?

Baldwin:

No, I did not get that until considerably later. In fact, I am not sure that I even looked at the Bulletin of the Philosophical Society of Washington.

Doel:

It is interesting that people at the U.S.G.S. didn't have a general sense that Gilbert had been involved.

Baldwin:

I imagine that many people in the Survey did know because there were people as late as the 1950s, like Dorsey Hager who argued that the Arizona crater was still endemic.

Doel:

That is, following Gilbert's point of view. Ok. One interesting thing is given the difficulties that you had had in getting the Astronomical Journal and the Astrophysical Journal
to publish the articles that you had written. How did you come to arrange with the University of Chicago Press to publish the book?

Baldwin:

I wrote to them and said what I had done and asked if they would be interested in seeing it: that I could send it or come over and talk with them. They said to send it to them. I did and in a few weeks they had contacted — I can't think of his name [Walter Bartky] and he had felt it was an interesting research paper and might very well be a book that they should publish and recommended that it be published. I do know this, which Gerard Kuiper refused to review it because he said to the Press, and they told me, that he didn't know enough about the Moon to warrant his being a referee. It was turned over to Fred Whipple. The only reason I knew about it is that Fred has a habit of initialing things and he initialed it on the manuscript. So I asked questions.

Doel:

Did you find out if he had any substantive ideas about your work? You had mentioned before that he had given you encouragement after reading the manuscript.

Baldwin:

You are talking about?

Doel:

Fred Whipple.

Baldwin:

He gave no input to it. I have a rather large file — in fact I have collected all my correspondence and placed it in various libraries — with Fred Whipple but none of it was other than the encouraging or some other subject.[1]
There really wasn't anything that those people could do because they hadn't studied it. They had an intuitive feeling, Whipple did; and Watson and Millman and so on, and Öpik. But none of them at that time had done any significant amount of studying it.

Doel:

What kind of reaction was there following the publication of The Face of the Moon among astronomers or geologists?

Baldwin:

I have had other people say the attitude changed suddenly with the publication of this book, and looking back on it I think it did. Very few people were involved in it. The book was issued in either 3-5,000 copies; five, I guess. It didn't sell very well. In about 1952 they wholesaled the rest of it. Then in 1957 or 1958 they came back and said "We still have a few of these left but they are going to be gone by such and such a time, we've got to reprint it." They asked if there were any changes I wanted to make and I said I was working on a major revision so I wouldn't make any substantive changes in it. I made a change in one formula and one gross error in typing, and that was about it. They reprinted it in a modest quantity and that lasted until The Measure of the Moon came out in 1963.

Doel:

You don't recall then any particular discussions about it after it appeared?

Baldwin:

Well, yes. Harold Urey got a copy of it — I think I mentioned it earlier.

Doel:

It is off tape.

Baldwin:

Well, Harold was a Nobel Prize winner in Chemistry. He got his award for something to do with heavy water, oxygen plus hydrogen 2, deuterium. He was working on the chemistry of the planets, which ultimately [as The Planets] was issued in 1952. There are three different stories as to how this came about but the one that seems to be closest to the truth is that Urey was at a party in Chicago one night and he saw a book which had just been bought by the host and it was The Face of the Moon. He picked it up and thumbed through it and then went over to the side and sat down and all through the party all he did was read that book. There are other stories about it too, but the reason I think this one is true is that Ursula Marvin told me the other day that that particular copy of The Face of the Moon had been given to the Harvard-Smithsonian Astrophysical Observatory Library by the people who were the host and hostess at that party. Urey got very interested in it and told the University of Chicago Press that that was the most important book they had ever published. Rollin Hemens was the editor at the press. He told me that statement by Urey. Urey began to get involved in studying it and then shortly after — he put a good deal of my work into a chapter on the Moon in his book The Planets — then he wrote to me. I had never met him. He wrote to me just about the time The Planets came out and I had ordered a copy of it. He said he would like to come to Grand Rapids from Chicago and meet me, and talk lunar astronomy. We set a date and I went down to the railway station and met him, came back and he stayed a whole weekend with us. We chatted, argued back and forth — the main argument which I had then originally with him and I had it until the end of his life was the fact that to me the Moon had to have been hot inside and capable of adjustment. He insisted that it was cold, that it was a primal body. We never did get together on that. I think the evidence is now clear.

Doel:

When Urey was giving his reasons, do you recall the range of arguments?

Baldwin:

The main argument that he had is that if the Moon were hot it should have settled down like a plate of fudge and all surface features vanish. My argument was that there are evidences of early lava flows, there is evidence of late lava flows — by late I am talking about after 3.85 as it turned out (billion years) — and my arguments were that you couldn't have lava without heat. If you had heat down low in the Moon's body a lot of it was still there. The Moon could not be cold. That implied — and I have had several papers on this later — a viscosity which decreases with depth in the Moon. Urey never would buy that. In 1962 there was what they called the Blacksburg Convention and I gave a long paper there in which I pointed out my opposition to Urey and his position on that and certain other points. Urey came down to the podium right afterward and said, "Since I seem to be the subject of discussion, I want the floor" and he tried to refute it. We each published in the reports of the meeting his challenge and my summary for it, and within a few years (recently) I got a letter from somebody — Benton I think — in which he called it the Urey lament. It probably did as much to establish my positions — before The Measure of the Moon came out — as anything except the chart on The Face of the Moon showing the relationship on a log-log scale of diameter and depth of craters. That was the key.

Doel:

Of course the controversy between Urey and others over whether the Moon had gone through a warm cycle or not was not only limited with you. He had a major battle over that issue (at least in part) with Gerard Kuiper in the mid-1950s.

Baldwin:

Kuiper's point of view was a little different. His idea was that there was a liquid layer below a crust floating on it and that the maria came when that crust was broken. Such a model is physically impossible. Engineering-wise that concept isn't valid.

Doel:

That was one of the things that Urey wanted to point out to you?

Baldwin:

He did. He pointed it out repeatedly and Struve made the comment one day, "There is only one astronomer in the United States that can get along with both Urey and Kuiper."

Doel:

That was you?

Baldwin:

That is right. We would argue and argue violently, then go out for a cup of coffee.

Doel:

When did you first start developing a relationship with Kuiper to discuss solar system research?

Baldwin:

It was much later but I can't give you a year on it. I visited him out in Arizona.

Doel:

So this is after the time he left Yerkes?

Baldwin:

I had been with Kuiper at Yerkes. He was there when I gave that first symposium. He really wasn't much interested at that time. You are right. I corresponded with Kuiper over the years but I don't really believe that he had a great deal to give on lunar studies. He had many other very positive accomplishments but I don't think his lunar studies were one of them during the early years.

Doel:

Do you recall any discussion by Urey, in particular, over other individuals who had — including yourself — strong opinions developed on the nature of the lunar crust? Are there other geologists and physicists who also have become interested that you might mention?

Baldwin:

There were some. I think maybe I could summarize it in this sense. If you agreed with Urey, wonderful. If you didn't agree with Urey it was proof that we didn't have enough facts so that people could agree. It wasn't limited to me. In fact, in a Blacksburg response in a challenge to me he used that expression — I can show it to you today.

Doel:

During the 1950s, when The Face of the Moon had appeared and you were doing revisions for The Measure of the Moon, did you develop contacts with any of Urey's students? Clearly some of them had developed ideas of their own.

Baldwin:

The only one of his students that I was really in contact with was a man named DuFresne. I think DuFresne was more on my side of the boat than Urey's, but didn't feel he should say so at that stage as a student. We got into a series of discussions on isostatic adjustments on the Moon and DuFresne was more on my side of the fence than he was on Urey's there.

Doel:

When was DuFresne a student? Was that the late 1950s?

Baldwin:

I think so.

Doel:

One of the great difficulties inherent in doing lunar studies from earth of course is that it is easier to see more detail using a visual study than it is to use a photograph. Even the best of photographs don't have the full detail that one can see on a really good telescope. How much opportunity did you have to use a major observatory telescope?

Baldwin:

I used the 18" occasionally, but my experience has been just the opposite. I felt that I could see more on a really good photograph than I could with the 18" telescope because then I had to record it in my own mind and it wasn't there for permanent continuing studies. I never had a chance to use the 100" or some big telescope like that and the 37 1/2" at the University of Michigan focused like a dish pan.

Doel:

So you felt more comfortable using the photographs?

Baldwin:

I did. I had huge collections from Lick and Yerkes and Mt. Wilson, later Palomar. The difficulty in fact-I think it is one of the key reasons why the knowledge of the processes that have operated on the Moon did not progress more rapidly — is that good scientists studied the Moon through a telescope or a spectroscope or a photograph even and were looking for finer and finer detail. The major discoveries on the Moon have come from an overall picture in relationships and big related features. In 1949 — in fact in 1941 and 1942 in my first two papers — I pointed out in addition to the markings radial to Imbrium, there were raised rings around them. I didn't have photographs, for example, of Mare Orientale, right over on the limb. We didn't have good photographs of Mare Humboldtianum, but Serenitatis, Crisium, Humorum, Nectaris and Imbrium all proved to be members of one family and they had these rings surrounding them. These included their main rim — external rings, sometimes inside rings and radial markings, both ridges and valleys. Have you read the book which was published on the giant basins on the Moon? They had a conference on that 8-10 years ago.

Doel:

Yes.

Baldwin:

Have you read the article by Bill Hartmann?

Doel:

That had been one of his main areas of work.

Baldwin:

Yes. Hartmann and Kuiper developed a means of projecting a photograph on a white globe and then photographing it from different directions. It brought out a tremendous amount of information.

Doel:

Right. That is what was going on at the Lunar and Planetary Laboratory.

Baldwin:

Right. Bill was absolutely sure that it was all his idea. In fact, I soon talked with Bill. I argued that he better do some reading in The Face of the Moon and my earlier papers, which he has done. He acknowledged it in one of his papers, giving the history of the development of knowledge. Then he quoted one of my letters to him which said, in effect, that astronomers for many years had been trying to learn more and more about less and less. And, that the big picture escaped them. They used the illustrations that we have just been talking about here. While Gilbert did discover the markings radial to Imbrium, he did not pick up these multiple rings. I am going to claim credit for that, back in 1941-42 and 1949. They were sort of a Rosetta stone in telling what had happened to the Moon and on a relative scale.

Doel:

Looking back on it now, do you think that was a problem characteristic in all of astronomy at the time, or was it related to areas where little other work had been done?

Baldwin:

There were maps of the Moon going back a century. There were very early maps, too. But starting, let's say, around 1850 relatively modern but small telescopes were put on the Moon and with the exception of Steavenson's observations of the valleys close to Ptolemaus, I don't know anything mentioned about those valleys until Darney — in 1933 — came out and pointed them out again. That was in a French publication and I did not catch that one early. Nobody was saying anything about multiple rings until, really, The Face of the Moon, and yet those things had been there standing out like a sore thumb. Nobody looked at the big picture. They all looked down at the little things. They weren't hard to see once you pointed it out. It's like Columbus and the egg.

Doel:

I might be wrong about this, but I don't recall that Spurr's study gave much emphasis on this either.

Baldwin:

I don't think he put any emphasis on it that I can recall. I have read his books but I didn't waste a lot of time on them.

Doel:

One might suspect that a geologist would be more interested in larger structures.

Baldwin:

Spurr's son was head of the physics department at Michigan State University twenty years or so ago. I was invited to give a lecture and I didn't tie in the name "Spurr" with the other one. I was warned just before I went on that he would be undoubtedly asking some questions and his father was this other man. I answered him as diplomatically as I could, but I did not think his father was right.

Doel:

That can be difficult to do.

Baldwin:

Yes. I think he still believed his father.

Doel:

When was this?

Baldwin:

About twenty years ago; 1960s.

Doel:

Of course we will talk about that in a moment, but Jack Green was very forceful in making that point as well. Just in thinking back, do you think there was any particular advantage that you were then in management and industry and doing that kind of science?

Baldwin:

No the things are too far apart. I can't say that other than the fact of being in the position that I was in the 1950s I was production manager and personnel manager for the company, and we had no modern computers or anything like that but we did have Friden calculators. I used the company calculators on various projects. I undoubtedly took advantage of the situation but I think I gave the company a very good part of my time.

Doel:

I am sure that you did.

Baldwin:

This was something I thought of for years and I may very well find something.

Doel:

During the 1950s, did you have any contact at all with others who were involved in issues of whether the earth had had unmolten history or not? People like Bollen, Jeffreys or Wilson.

Baldwin:

Not Wilson. I corresponded with and met Jeffreys who has recently died. Jeffreys was not involved in the history of the Moon in any sense except as a body moving around the Earth. We didn't have a great deal to discuss. C. S. Beals in Canada read The Face of the Moon and somehow or other got then interested in reexamining the Canadian Shield, which was a very ancient region of rock. He got government support for an aerial survey. He and Mike Dence, one of his students —
Doel: This was at the Dominion Observatory?

Baldwin:

Yes, up in Ottawa. They got into a major program and they found a very substantial number of impact craters — the largest of course being Manicouagan. But then there are the two Clearwater lakes craters. These are big craters and there are others – Carswell — up there. But Ian Halliday wrote — when I was elected an honorary foreign member of the Royal Astronomical Society of Canada — that very probably without my earlier work that program wouldn't have been undertaken. Beals was always very much of the same point of view. I can show you a letter or two of his.

Doel:

This was the 1950s?

Baldwin:

He started in the middle 1950s, as I remember, to go after these craters. He spent a long, long time. I went up and visited him once and it turned out — we had an appointment — to be a very bad time to visit him because the IRS or whatever goes for that in Canada was up analyzing his finances. He came out clean but it took time.

Doel:

Did you have extended discussions with him then in the 1950s about crater processes?

Baldwin:

Not so much process as relative dimensions. He wanted to know, for example, if they cored a given crater how far down they would go before they should come to a boundary — an in-fill boundary.

Doel:

Past the breccia, in other words?

Baldwin:

No, on top of it before hitting the in place breccia. I showed him how to use the equations that I had developed. They were all wrong for the very smallest craters, a few feet in diameter, and I corrected that for The Measure of the Moon but when you get above about 30-40' they were pretty good. He drilled — I have forgotten whether it was Holleford or Brent, I think Brent — through the ice and cored out several places in there. He would find the border between the effective visible surface of the crater and the in-fill, almost exactly where my equations would indicate. This justified in the minds of Beals and his backers that they were on the right track. These were impact craters. He always said that was a very satisfactory thing, the first time when they went down. I think I predicted 1,061' and it came at 1,049' or something like that. They brought up that core and measured it. That was it.

Doel:

That must have been exciting for you too.

Baldwin:

I wish I had been there. I visited Beals up in Canada but not out in the field.

Doel:

Did he talk to you about the reaction of other geologists in Canada?

Baldwin:

He was quite bitter that many of them wouldn't accept.

Doel:

Canadian Geological Survey members, in particular, were opposed to his interpretation.

Baldwin:

Astronomers accepted the impact hypothesis very, very quickly and the geologists were much later in accepting it. He told me once (he wrote it in a letter) that he presented a paper in some meeting up in Canada and this old-fashioned geologist stood up and ranted about this impact theory. He said, "This foolishness has gone around the world." Beals was very happy with it and quoted it on various occasions.

Doel:

What sort of man was Beals? How well did you get to know him?

Baldwin:

He always was very open and friendly with me. He was easy to meet and talk with. He was older than I am. I would say he probably was 20 years older. He had a rather square face, good solid jaw, mustache sometimes (maybe always), and was a good scientist. He knew what he was doing and he never went beyond his data.

Doel:

Did you say he had a number of students at the Dominion Observatory who were also working on the field project?

Baldwin:

Yes. Innes, I think, was not one of his students. My guess is that he was on the faculty there. M.J.S. Innes. Mike Dence was one of his students. When I was up there they had a picture of Manicouagan on the wall. They hadn't published it. They were pretty much of the opinion that was an old impact crater and I tried to encourage them to publish it because I think any information, even if it is wrong, should be gotten out and thrashed out whether it is right or wrong. It, of course, was proven to be right. It is about 70 km in diameter, something like that.

Doel:

Of course a very remarkable shuttle photograph has been made of it.

Baldwin:

I have a book in the next room which shows that photograph.

Doel:

I am just curious if you had any conversations with others who were working on the geo-physics of the earth and the thermal evolution — like Louie Slichter or Bill Rubey?

Baldwin:

I have talked to Rubey but never Slichter. We didn't have any real points of argument on lunar history. The people that you talk to mostly are those that want to argue with you. You mentioned Jack Green. Is this the time to get into Jack Green?

Doel:

Let's hold him off for just a moment.

Baldwin:

I can hold Jack Green off a long time. In fact, I think I will.

Doel:

Let's hold it off. Were you aware, say through conversations with any of the participants of the conferences on the earth's evolution such as the Rancho Santa Fe meeting? Were you thinking about going out to any of these meeting?

Baldwin:

No, I couldn't go out to many meetings. That has been one of the objections about my work that I kept aware of what was being published but I couldn't get to the meetings and talk to the people very often. I think one of the first meetings that I attended came after The Face of the Moon was published in 1949. For a period after that I was collecting information which I thought might serve for a revised issue of that book. I finally began to realize it was too much and that it had to be a new book — a sequel and not a revision. Sometime in the 1950s there was a program put on on impact cratering by Rand in Santa Monica. I was invited although my security clearance had lapsed and they had to get me a new top secret — why this was top secret I don't know, but it was — clearance for people. I got out there for the meeting and my clearance hadn't come through. So they finally declassified one session and I gave my talk but then I couldn't read my own talk afterward! That was more or less an impetus to really start work more seriously again on The Measure of the Moon.

Doel:

This was the late 1950s?

Baldwin:

I am going to guess about 1955.

Doel:

So prior to Sputnik?

Baldwin:

Yes.

Doel:

Was that one of the first major symposia on cratering that you can recall? There were others in the early 1960s.

Baldwin:

There were others but as far as I know that was the first one. Being classified, I never saw the publication.

Doel:

Were you aware of others who were participating in it?

Baldwin:

Oh yes. I knew about Lampson's work by that time and there were several. I shouldn't try to say who they were because my memory isn't clear on that. But, there were other astronomers and physicists, and geologists who were there, whom I knew or knew of.

Doel:

How many were at that session?

Baldwin:

100, around there.

Doel:

That is all quite interesting that you didn't get to read it afterwards.

Baldwin:

I always kind of enjoyed that.

Doel:

I am curious if during the 1950s if you were in contact with various people who were at work on meteor craters, La Paz, for example? Or Harvey Nininger?

Baldwin:

I never met La Paz. My only contact was when I published an invited paper in Scientific American and he made some foolish criticism of it]. The first time I met Harvey I went out with my father, mother and wife to Camelback Inn where we had an association of the Woodworking Machinery Manufacturers of America. We were members of it. Dad was the past president, I was a future president and my son was a future president of it. I wrote him that we were going to be out there and I would like very much to meet him. We had corresponded before. We would like to go to the crater. He wrote back that he would be delighted and we met him in Sedona. We drove up there with a leased car and then drove over to the crater. Afterward we finally went back to Sedona, then returned to Phoenix and flew back from there. Harvey — he was a wonderful man — rough-hewn, short, rather delicate individual but he was tough as nails in spite of that. He died at 99, two or three years ago. This was in the 1950s, so he was probably in his late 60s at that time. He and I scrambled down the north wall, walked across up the south wall and back around, and he talked all the time. He loved that crater and the things that he had found there. He showed me in this museum the little round, almost dust-iron droplets and showed me the analysis of them which showed that the nickel was increased in proportion above the solid meteorites which were found and the cobalt was increased even more, meaning the iron was selectively oxidized (I suppose) away and the nickel less so and the cobalt least. The integration of what he had found and some estimates around the crater, indicated something of the order of 20,000 tons of that material were spread around the crater in dust-like form. It was absolute evidence that the meteorite itself (the asteroid if you want) had vaporized on impact and that Barringer was dead wrong. There wasn't any punch-like big meteorite down at the bottom for him to mine. Thank heaven he persisted and he established in 1906 that it was an impact crater. He wouldn't have done that if it hadn't been for his erroneous idea.

Doel:

Baldwin:

Doel:

Yes.

Baldwin:

I think that is a very fine book. Hoyt gathered enough information about Barringer that would have otherwise been completely lost in the early history.

Doel:

There were others by 1959 that were looking at the effect of exploding nuclear devices above and below the surface, including Eugene Shoemaker and others in the Geological Survey under your contract for the Atomic Energy Commission. How much did security classification of that research hinder communications by those who were interested in applying these results to impact craters?

Baldwin:

I can't answer that because I don't know how much material was actually developed. But, Shoemaker and I corresponded and there was a large amount of information which was put into the literature. We had no difficulty in discussing Jangle U and the other explosive craters; or rather I should say nuclear craters, which were produced at that time. I am sure some of it was classified and never got out but an awful lot of it did get out.

Doel:

Did that mark in your mind as well a new period of understanding of the relationship between explosive energy and meteor craters or was that more of an evolution?

Baldwin:

It was a continuously developing field. Yes, it helped. No, it did not establish the order of magnitude of the energies. We had pretty well pegged that by that time and in my work on energies I used the crater form more than the energies in developing the relationships between diameter and depth and rim height, and so on. The biggest crater that ever was produced by explosives — I can't remember the name but it will come to me — was about a quarter of a mile across and perfectly beautiful symmetrical crater and gave me a very good point. It was Sedan. But by the time the atomic program had developed, the basic curves were there and it is just a little refinement here and there on the curves that they produced. The energies, if you say that a given number of ergs in a nuclear explosion will produce the same size crater as a given number of ergs in a chemical explosion or an impact explosion, then I don't think it helped a great deal. But, the partition of energy in the three kinds of explosions — three kinds of crater-forming events — are not necessarily the same. Shoemaker and I have always been on slightly different sides of the fence; not too far apart but still different on the mechanism by which a crater is formed. He says that it is formed by the shock wave moving through and moving the accelerated material. I have had the position that it is fundamentally an explosion. You do transmit energy by shock wave but the meteorite itself explodes because it is vaporized. Some of the rock is vaporized also and the difference should be relatively small. I think it is more semantics than anything else. I don't think we are really too far apart because the energy figures we come up with are not too far apart.

Doel:

Didn't the work of Don Gault at Ames address that question?

Baldwin:

Well, I don't know that Gault has ever tried to tie it into nuclear explosions but he has done a great deal of work on in-vacuum collisions with particles — glass, aluminum, rock or whatever — that are moving at very high speeds (maybe 7-8 km per second), at various angles of impact, various types of target material and has published a huge amount of material on that. In fact, when I got the Leonard medal from the Meteoritical Society on the same day Don Gault got the Barringer medal. I have a picture of the two of us that John Wood took.

Doel:

It may be helpful, if you have time to place copies of photographs in the Library of the American Institute of Physics.

Baldwin:

I have very few photographs of any kind left. I had the complete set of Orbiter pictures of the Moon.

Doel:

Not the scientific, but those of yourself and others.

Baldwin:

I don't have much. I would like to keep this one but I could give it to you if you would like to make a copy of it.

Doel:

I was thinking about the late-middle 1950s. Did you have any involvement at all with the U.S. National Committee of the IGY — had you thought to become involved in this kind of research?

Baldwin:

No. I had enough work in my own field to keep going and I was preparing — for ten years — The Measure of the Moon. In fact, Bob Dietz reviewed the manuscript and he wrote to the University of Chicago Press that "if Baldwin has done nothing for the last 13 years but prepare this book he hasn't wasted any time." So, I was busy. Really there wasn't a heck of a lot that I could get from outside people because nobody was really working in the same directions that I was working in. That has been one of the good things and bad things about my career, that I was alone.

Doel:

What kind of interactions did you have with Bob Dietz?

Baldwin:

I have had wonderful relations with Bob.

Doel:

When did you first come in contact with him?

Baldwin:

Let me think that one over. When The Face of the Moon came out, I had missed Bob's 1946 paper. Either he wrote me or somebody else wrote me about it and then I wrote to him. I apologized for it and I mentioned it several times in public since. Bob said many of the things that I had said in 1941 and 1942, but I never mentioned to him that he didn't mention those papers either. We have met at various meetings since and corresponded frequently. At one meeting held in New York, Bob was on the stage and he was talking about the crater that had to be to produce the australites. He tried to tie it into the Elgygytsen crater in Siberia. I stood up and I said that "Bob, I just can't buy it. That crater just isn't big enough to produce these observed effects." He said, "Oh yes, it is. Did you want to bet on it?" I said sure, I would bet a dollar. This was audience to the speaker. He said, "Okay you're on." In the meeting of the Meteoritical Society in 1986, for some reason or other when I came into the auditorium I sat next to Bob. I said, "Bob, do you still think Elgygytsen was it?" He said, "No." I said, "Alright, you owe me a dollar." So he reached in his pocket and gave me a dollar. Then he said, "Well, I'm only 99% sure, so you owe me a penny." The next day I paid him a penny. We have had a lot of fun with that. One of the later speakers had overheard the conversation and he repeated it to the group!

Doel:

That's a good story. Were you involved in the AGU prior to the 1960s?

Baldwin:

I think I joined in the 1960s. I would have to go back and check on that.

Doel:

But you had been more actively involved in the IAU?

Baldwin:

Yes, I attended some of their meetings but — except England — never abroad.

Doel:

You were at the Berkeley meeting then in 1960?

Baldwin:

I went to Berkeley once but I don't remember whether that was it or not.

Doel:

Do you remember discussions at any of the Division 16 meetings in the 1950s or 1960s about beginning plans to develop more extensively solar system research? Are there any things that stand out in your mind particularly?

Baldwin:

I don't think there was any argument. People were beginning to realize that there was a tremendous amount of work needed to be done on the solar system. It was a much neglected part of astronomy. Everybody was interested in stars, then in Nebulae, then in cosmology, red shifts, dark matter, and that type of thing — the commission 16 on the Moon ultimately became two commissions on the solar system and on the Moon. I am not sure whether they have recombined them now. I haven't been active in it for several years. The discussions that were held were all positive. Everybody felt that a lot of work had to be done and they wanted to be part of it.

Doel:

Did you play any particular roles for them in the 1950s and 1960s?

Baldwin:

No. I didn't attend often enough to be a regular on that. I just couldn't.
I was offered the Presidency of Commission 16, but regretfully I had to turn it down.

Doel:

I realize that I did not ask you what Oliver Machinery was producing?

Baldwin:

Oliver makes woodworking machinery of many kinds, largely for pattern shops and furniture plants. They are world leaders of sawing of metal-making machines to do that.

Doel:

Were you involved in any research involved in those industrial techniques?

Baldwin:

Very definitely. In fact, I was production manager for a while, then general manager, then later vice-president and president — always in charge, after the first few years, of that particular division of the company. For example, in about 1970 I conceived of the desirability of a computerized cutoff saw in which we would identify the portions of a board that needed to be cut out for knots and cracks and defects like that, and you have various lengths of clear wood in each board. What is the optimum way to cut that clear wood up against a bill of materials? Well, we developed a machine and we are still developing, still world leaders in that kind of equipment. Right now one of our machines will measure the width of the board, take a bill of materials which is applicable to that width only and cut up in various ways any section of clear wood that goes through. It will do it at about an average of 150' per minute. You might say, "I want the absolute maximum against this bill of materials." Usually it will come out with a zero or very little waste wood. But you may not get the distribution of lengths that you really want. So, we have to bias it towards those lengths. There are various ways of adapting the machine to that. This machine will now handle ten different bills of material at the same time based on width of the board. We'll cut them up and we've developed sorters which will sort the wood where it belongs. That is complicated. We have developed sawing machines for first aluminum and other non-ferrous metals; copper, beryllium, brass, etc. Nickel, steel and stainless steel came later. We have on the floor now a machine which will be shipped in January which will cut titanium, aluminum, or steel up to eight inches thick, 20' long. It is all straight line cutting. It means a tremendous saving to a company in inventory. They can cut what they want out of a big plate. They may only have to keep only 10% as much steel on hand as they would otherwise.

Doel:

Did you ever find that there were particular parts of your scientific training or career experiences that helped you in developing these techniques?

Baldwin:

Not specifically but as I think I mentioned earlier, I am kind of a funny duck. My mind works in a little different fashion than those of many other people. I see answers to problems, usually correct, not always, rather quickly. As a result — whether it is a matter of logic or what — when a problem is presented I can often see a way to solve it like the problem of an optimum method of cutting wood or cutting steel. For example, we had a saw to cut copper once to make huge bus bars and we shipped the machine, we tested it in the plant and it tested very well. The customer couldn't get long saw life. It wouldn't cut enough before the saw became dull. The machine was sent back to us and they said, "You take this machine back. We will buy a machine from you if you can cut 100,000 square inches of copper before resharpening." They set up a series of specifications. With the facts in front of me — the results of their test cutting — I sat at my desk for about two days analyzing those and finally came back and said, "If we make a machine to these specifications — including the projection of the circular saw blade above the top of the work so that we are cutting down and not scraping going through — we can do it." So, we took a gamble and said we could do it and how much the machine would cost. They said they would take it provided "before we accept it in your plant you run a test on our copper and you get 100,000 square inches of cut before you have to resharpen the saw blade." We agreed. The first machine was cutting 3,000 square inches and we got 100,000 on the new machine. It is still in operation down in one of the Amboys of New Jersey. I don't think that has a darn thing to do with what happened on the Moon but it is the type of thing that I like to do.

Doel:

How did you resolve such problems when they occur?

Baldwin:

For the lunar craters, for example, first I laid down what are the problems — what are the things that we don't know — how were the craters formed — how were the rocks formed — what were the dark areas and so on. The Face of the Moon and the two earlier papers were primarily unquantified publications. In The Measure of the Moon I endeavored to quantify each operation as best I could to come up with numbers that were meaningful. That is the type of thing I told you about earlier that I would simply lie back at night very often concentrating on this darn thing, "So now if this what that," and so on. Gradually the picture unfolded and I put it down in black and white.

Doel:

Let me just ask you one general question. At any point during the 1960s, when interest in the Moon had accelerated enormously, did you have offers to leave Oliver and directly become involved in lunar research?

Baldwin:

Yes, I can give you one. There were others but I will just name one. I was offered the chairmanship at the Department of Astronomy at Northwestern University. I had been at Northwestern for four years before the war. I turned them down and said I wanted to stay where I was and do what I was doing here. I thanked them very much for it. The offer was made by Gerard Kuiper who was talking with and for, I believe, Dean Simeon Leland. He was one of the deans of Northwestern. When they found that I wasn't going to come, they gave the position to J. Allen Hynek. I knew Allen. I worked throughout the war with Allen. He was head of our records library but he was a lot more than a librarian. He never knew I had been offered his position.

Doel:

What kind of impressions did you have about Hynek when you first met him? How well did you come to know him?

Baldwin:

At APL?

Doel:

Yes.

Baldwin:

I knew him before that. He was with Ohio State University and another school just north of there that had a big telescope. I knew him from that. We had been down and seen his observatory and department there. Allen came to the laboratory, I think even a little before my coming but I am not sure of that. He was on his honeymoon when the war started, and he was down in the Washington area. He contacted various people to try to find out where he could be of use. He ultimately was sent to the Applied Physics Laboratory because somebody heard he was a ham radio operator. He got a job with the Applied Physics Laboratory but it had nothing to do with his radio, even though it was a radio fuze that was being developed. They needed somebody with an orderly mind who would handle the massive doses of paper we were going to be turning out. He took that job. I think he came there a little before me. Allen — honest, sincere, enthusiastic, probably a good leader but not a research man.

Doel:

His inclination simply wasn't towards doing research?

Baldwin:

He wrote a book on astrophysics and frankly I can't tell you a single thing he published other than that.

Doel:

In late 1945, he and George Gamow had reviewed von Weizsäcker's study of cosmogony, which he had published during the war. Did he talk to you about how he got involved in that?

Baldwin:

We had a dinner party during the war in which Allen and Mims (his wife) were coming. He called up and said Gamow was going to be in town at that same time. "Was there any chance of squeezing him in?" So we did. Allen, Gamow and I spent the evening discussing his big bang hypothesis and I remember his talking about neutrinos at that time, before they were even publicly known I guess. That is about the only contact I ever had with Gamow. I had one other memory of him, too. He asked for a second of dessert, so he got mine!

Doel:

That is quite a way to remember him.

Baldwin:

Gamow was a pioneer if there ever was one.

Doel:

There were other offers you had as well for possibilities of working in astronomy?

Baldwin:

I never got to the stage of offer. There were discussions, so I don't think I better go into detail. There were some, yes.

Doel:

Let me just ask you what year that was you had the offer at Northwestern?

Baldwin:

It was a long time back, not too far from the time of the Korean War.

Doel:

Not really too many years after the World War II?

Baldwin:

I am trying to remember the name of the man from the Applied Physics Laboratory just about that same time — H. H. Porter called me and asked me if I would come back to the lab because the Korean War was imminent and it looked as though they might need considerably expanded facilities. Well, you can find out when it was. Also when did Allen get in at Dearborn — because it was in the six months or so before that.

Doel:

Realizing that you intended to stay at Oliver, were you tempted if that other responsibility had not been there would you have gone to APL?

Baldwin:

Yes, I would have in this sense. This country has been good to me. In its time of trouble I felt and I still feel that each person has to do what he can to help the welfare of the nation. The Applied Physics Laboratory did a tremendous amount of good during World War II and if there were an opportunity and a need I felt that I should go down there. I did not go because I had family responsibilities, both personal and in the company that required attention at that time. We could help the war effort to a certain extent from our own company. I can give you a minor example of that. We sold band saws. During the war when I was not with the company, they sold them to Piccatanny Arsenal, a stripped down version. Every once in a while there would come an emergency order for another one just as fast as we could get it. It turns out that what they were doing is sawing through shells that had been loaded with the explosive. They set it up in an automatic fashion with lots of baffle walls between you and the machine. What they were doing was testing for the smoothness of the explosive in the shell and were there any cavities. On setback from firing the gun, the material will fall down into the cavity and often detonate. Every once in a while it would detonate and they would need a new band saw.

Doel:

I would like to get into detail the lunar research that you were doing by the 1960s. I think by the early 1960s one of the main projects you were working on was the crater scale — the scaled depth of burst relationship.

Baldwin:

That was a little earlier then. I had essentially completed it by the end of the 1950s or early 1960s. I took the basic work from The Face of the Moon and much of that work on smaller craters was on shell and bomb craters and I eliminated those because they usually are fuzed to the point where the fuze will hit the ground and a super quick fuze will blow up and much of the shell will still be above the ground. Generally this means a shallower burst than is normal. The relationship between diameter and depth was not a true relationship for lunar crater purposes. In fact, the smaller the shell the greater distance it penetrates relative to its own diameter. The big huge lunar craters are practically surface bursts. They may go down 30 km but that is small compared to 1,200 km across. I made friends with a fireworks man and he used to make me explosive charges of weighed amounts of various explosives. I knew the energy of explosion of these various materials — blasting powder, black powder, TNT and so on. I ran a whole series of tests and filled in that bottom from a few feet down on the curve and modified that. In the meantime, other people were measuring diameters and depths and rim heights of craters, and publishing them. I collected all that information that I could and threw out a little that didn't seem to fit at all, using statistical methods. I revised the relationships. Those are the ones that were published in The Measure of the Moon but were completed essentially about three years before the book was actually issued. The neighbors didn't like all the noise. I did some of it down on the shores of Lake Michigan.

Doel:

That was at the Michigan cottage?

Baldwin:

Yes. That is in sand. You've got to act fast to interpret a crater because sand will collapse if you don't watch out. So we had some that was just slightly damp and it wouldn't collapse as fast. Then I made a few models with sand of different colored material, in layers. Then I set off these charges and developed a cross-sectional picture of just what happened to various parts of the layers; how much was turned over and how much was gone and how much was pushed down in, and so on. It was rather interesting.

Doel:

It was a rather fortunate friendship then?

Baldwin:

Yes.

Doel:

Aside from the literature search was there any other direct data that you were gathering?

Baldwin:

I searched. I kept in touch; I would go down to the Naval observatory or some other library every so often and then review everything that had come out since the past date. Marjorie Klopine at the Naval Observatory — I guess she succeeded Grace Savage — was a great help to me. Every once in a while she would say, "I've got something for you." I'd ask her to send it up. Sometimes yes and sometimes no. Let me tell you a story. Take it off — you don't need it on this.

Doel:

Are you sure?

Baldwin:

Well, ok. There was one gap in the diameter vs. depth in rim height that I wanted filled in. So I calculated about what explosive energy would be required and it took a quarter pound of blasting powder. I went outdoors to make the test and it had frozen that night! The ground all had a crust of frozen ice and mud. That wouldn't do. This was Sunday morning and I finally called Eugene Martin, who was the superintendent of our foundry. I told Gene my problem and asked if he could make me, with foundry sand, a box about five feet in diameter and about so deep where we could run this test. He said, "Better yet — I have a big pile of new sand which we can just level off in five minutes down near the slinger in the foundry and we could run the test there." Well our foundry — this must have been about 1956 — has been in operation since, I would say, 1900. We went down there and I tried to fasten a long fuze to the charge and the only thing I could find to fasten it with was a paper clip. The fuze burned so violently that it pulled away and it wouldn't light the little short fuze that was on the charge. We wasted all four of these long fuzes that I had and still nothing happened. Gene said, "I guess we have to go home." I said, "No, have you got any newspapers?" So we found an old newspaper and put it down so we could burn it and the burning would go to the fuze, the fuze would light, and the charge would go off. I lit the newspaper and watched to make sure it was progressing properly and then Gene and I stepped behind a bunch of flasks in a protected area. A flask is a metal framework in which you make a casting. The mold is made in it. These flasks were piled solid and offered good protection. We waited and nothing happened. Gene wanted to go out into the open bay to see what went wrong. I wouldn't let him. Shortly thereafter he said:" I'm going to look." I said: — "Gene, stay here!" Then he said: “No, I am going out." Well he went out into the open and got about 30-40 feet from the explosion. I can still see him. It went off, "bang," and Gene ducked, standing there with his hands up and then he looked up and said, "My God," and here came dust down just about this speed — slowly, like a curtain — an absolutely opaque curtain. And it went down on Gene all the way to the ground. He came swinging his arms and that peach-colored suit of his was never the same. But, we got the data that we wanted.
The next day — Monday — the men came into the plant and started asking questions, "What had happened to all that dirt," that was thrown over everything? The explosion broke a window almost as far away as that building.

Doel:

That is a good 300 feet away.

Baldwin:

Maybe not quite that far — maybe 100 feet to the window. But an explosive charge of just a quarter of a pound of blasting powder in an enclosed building, that is noisy! I have told that story many times.

Doel:

This is certainly an interesting part of lunar research.

Baldwin:

Yes.

Doel:

Do you recall any details from any of the unclassified crater symposia? There was one in 1961, for example, that was held at the Carnegie Institute in Washington.

Baldwin:

I am trying to remember the name of the man who was doing a lot of that. I had his publications; the man who was in charge of many of these explosive tests and he would publish papers on actual atomic explosions, on the theory of digging ditches like canals and so on. I had a big file on that. I never attended his meetings but we did correspond. I can't think of his name.

Doel:

We can add that later.

Baldwin:

I would have to go back to Grand Rapids before I could find out.

Doel:

What, as you think back, was the main reason why the symposium was held? What were the interests of the participants?

Baldwin:

I think the main reason was the possibility of commercial use of nuclear explosives. At that time they thought they could use it. As I said, to dig canals or to block something and so on. They had tests of two and three explosives set off at the same time or in sequence to see what kind of a crater and wall would have developed from it.

Doel:

Had you participated actively in such symposia?

Baldwin:

No, I didn't go to that meeting.

Doel:

Did you attend any of the subsequent ones?

Baldwin:

I never went to any of that kind of thing. I had the information by that time that I needed. I was interested, I got the publications but there was very little that I did use. When I got information on Jangle U and Teapot Ess and others, those nuclear explosive centers — I could use those on my curves. I got a letter from Florenski in Russia one day, which he had recently discovered the Zhamanshin crater there and he commented that he had now put one more dot on my curve.

Doel:

When was this?

Baldwin:

I have that particular comment on that letter. I can get it here for you.

Doel:

We'll check on that. It was in 1961 when you had published the contour map of the lunar front faces.

Baldwin:

Yes.

Doel:

How many years had it been that you were developing the data necessary?

Baldwin:

About four. I shouldn't say that — it wasn't that long. It was that long since I started the project but I hunted and hunted trying to find a measuring engine that I could use. They either were unsatisfactory or couldn't be moved. I finally learned that Northwestern University had one. I don't know where it had been when I was over there. I never saw it before. I contacted Dean Leland and he had me take out an insurance policy on it, and I came over and got it. They had wrapped it and I put it in a special room that I kept locked in my basement and did the measuring there on plates which were furnished by Lick Observatory.

Doel:

Right. Those were the 36 inch refractor plates.

Baldwin:

I took, finally, five plates — two of which had almost exactly the same vibrations. They were at widely different phases, however and covered different parts of the Moon. I had always two plates and sometimes three plates for every one of the 696 points. I started with something a little over 700, perhaps 730 or so, and then threw out some of them before we got through. My son, Dana, went down into that basement room one day. I was working on the first plate and he bumped the machine. He didn't do any damage but he did change my adjustment. He thought that he hadn't done anything to it. It looked just the way it usually did, so he didn't say anything. He 'fessed up immediately when I came back and said, "Somebody's bumped this machine." He was really shocked to find that it was that sensitive but I was measuring to 1,000th of a millimeter and I could reproduce my measures with a very small probable error. Getting the measures on these plates — and each one was measured either three or four times — in each direction and then the plate rotated. I then solved the measured position for each and then I had to correct for parallax, for refraction (differential refraction) over the plate, instrumental corrections and so on, using Schrutke-Rechtenstamm's positions as fundamentals. I have tried to re-reduce it since then on better fundamental positions but it doesn't make any significant difference in the contour map. I think the contour map is still rather good. In fact, Don Wilhelms made this comment two years ago. He said that "this contour map, except for the areas covered by the altimeters on the Apollos, is still the best there is." It was that contour map that really first put me in touch with Öpik.

Doel:

Is that so? How did that come about?

Baldwin:

I was telling you that I had corresponded with him a little bit but then at the meeting at Columbia University, he didn't know I was there and he didn't know me by sight. He made some favorable comments about this map. Afterward I went up and introduced myself and we spent more than an hour talking and then later walking together on that day. He was a smart cookie!

Doel:

He's also worked in quite a few different fields.

Baldwin:

Not only different fields but different locations. He worked in Samarkand and in Tashkent and in Armagh, Ireland and the University of Maryland — all over the world.

Doel:

What sort of impression do you have of him as a person?

Baldwin:

I have a tremendous respect for that man's intellect. He was very intense, very interested, and very accurate. I have really nothing but respect and admiration for him.

Doel:

Do you recall discussions that you had with Öpik about cratering at the Columbia meeting?

Baldwin:

Only a limited one and I was on a different side of the fence from him. It is really the only error I know Öpik ever to make. He published some papers on impact cratering in which he stated and used formulae based on the dimensions and based on transferable momentum. Right from the beginning, I had used kinetic energy which is the right one. When I tried to apply his formulae to craters of different sizes and I found some craters where the meteorite was bigger than the crater, which just is impossible. I think he came around finally, but it was a long time.

Doel:

What kind of meeting was it at Columbia? A general meeting, or was it one devoted to one issue?

Baldwin:

I wish I could answer that — it is so long in the past. It either was a special conference called for something like that or as a group that were interested in that subject, attending an American Astronomical Society meeting and I can't tell you which one it was. It probably was the latter.

Doel:

What was it in particular on the lunar map that interested Öpik or was it just the interest that the two of you shared?

Baldwin:

I think the thing he was most intrigued with is that the lunar map shows very clearly that the Maria are low. They are down an average of about 1-2 km over the mean surface. That by itself is pretty nearly definitive proof of the action of isostasy on the Moon. I think that is why he was interested.

Doel:

Was that a result that you had expected? Were you hoping to get that when you began?

Baldwin:

No, I knew I would get it because there had been earlier maps which were not very accurate but they gave us — when you analyzed the data from which they were formed correctly, they showed that the Maria were lower and I covered that in The Face of the Moon. In fact I show the earlier data separate. Nobody else had ever separated them into Maria data heights and non-Maria heights. Some of your questions are very difficult to answer in the sense that I don't think you have realized how alone I was in this darn field. So many times there would be a meeting and they would be going over something that I had already gone over. It is a most peculiar position to be in.

Doel:

When did that start to change for you?

Baldwin:

With Sputnik.

Doel:

So through the 1960s you really felt that you were inherently part of the community?

Baldwin:

I went in 1962 to the Blacksburg Convention in Blacksburg, Virginia and one reporter came up to me and he said, "What school are you with?" And I said I wasn't. He asked, "How did they let you in?"

Doel:

Would it be very frustrating?

Baldwin:

Frustrating but enjoyable.

Doel:

How did the science itself change or the way in which it was done after NASA was created? You had such a strong, direct interest in lunar science.

Baldwin:

A substantial number of people got into the field. There were huge numbers of people working for industrial concerns and for NASA and so on. They were trying to find out, "Was Tommy Gold right, would a vehicle sink down in deep dust and be lost," and so on. That type of thing happened and we spent a fair part of our time refuting that. In fact, I even coined a term once. I was giving this talk at Blacksburg and I called the dust movement that Gold had specified as a new form of Goldian Movement. I think I got a laugh.

Doel:

I recall the "Gold dust" too. That was also the time you were beginning to do the consultancy work for Boeing?

Baldwin:

Yes it was when they were preparing for the Moon landings which they knew would be coming. They wanted to know as much as they could ahead of time. I gave lectures at Boeing. I was out there when the first 727 was flown. It had spoilers on the front of the wings and the hydraulics were not strong enough. They couldn't deploy them properly. The thing came in at about 300 miles per hour. They got it stopped with about 20' to spare at the end of the runway!

Doel:

That must have been a heart stopper.

Baldwin:

It was. Then I gave two talks. On one occasion and one later on at the Lunar Planetary Science Institute in Houston. I had meetings in Grand Rapids and also down at Chance-Vaught. There were quite a few meetings with industrial firms. I would travel to them and go over the situation as we knew it about the Moon and just update their people, or in some cases they came to Grand Rapids.

Doel:

Did you have any strong feelings one way or another towards the manned effort, towards developing the Apollo project?

Baldwin:

I was very much in favor of a manned effort. I think both manned and unmanned trips should be pursued. The Russians succeeded in sending vehicles to the Moon and scooping up some regolith and bringing it back. But they never learned a great deal from that in comparison to what we learned from the rocks that were brought back. The source material was too confused. We learned some things. The unmanned programs were nowhere nearly as successful at that time. We didn't have the equipment then to really make a true, unmanned landing and selection of materials and so on and so forth. If we ever landed on a moon of Jupiter or Pluto and we had a vehicle it would be one of the most frustrating things in the world. You would have to wait an hour for Jupiter and several hours longer for Pluto to give an instruction, do this and then wait that length of time for it be done and have the vehicle send back its message and report and then do it again. You wouldn't accomplish much. I don't think that we can even today send a vehicle to Jupiter with the best of controls and land on one of its moons and accomplish a great deal with the vehicle there making all the decisions on what it did. On the Moon, yes.

Doel:

Didn't Merle Tuve strongly disagree with the manned program?

Baldwin:

Yes.

Doel:

Did you ever talk with him about that?

Baldwin:

No I did not. But I know he disagreed with it. It is one of the few things I thought Merle was wrong on but I wasn't going to take the time during the war to talk with the man running the laboratory on something like that. I talked with him after the war; I had many conversations and visits with him when I was writing The Deadly Fuze.

Doel:

I'm sorry. I didn't quite understand the connection that you made there, on disagreeing with him?

Baldwin:

I did disagree with him about manned landings on the moon, but I didn't argue or talk with him about it because he was so busy during the war. [Added later by Baldwin] Remember, the APL was involved in rocket research with captured V-2 rockets and we all assumed ultimately we would go to the moon]. After the war I didn't see him very much. I didn't get together with him until I was writing in the late 1970s. By that time he was a dying man.

Doel:

During the 1960s?

Baldwin:

Very little contact. I would say hello once in a while if I would go through town, by telephone. He lived in Chevy Chase.

Doel:

I am going to turn back to that particular research in just a moment. Did you have opportunity to join with the science teams that formed around the various lunar programs?

Baldwin:

Only one of them and that was Orbiter. With Orbiter there were five planned. NASA thought that the statistics were such that only three would be successful. So they laid out programs for three. The first three were successful and they called a group of scientists down to Washington and a man by the name of Martin Swetnick ran the meeting. He gave what I just gave you. The three were successful and they wanted to get the most out of the remaining two that they could. What should they do?

Doel:

That was to make them science missions as opposed to mapping for the Apollo program?

Baldwin:

Yes, although it did not turn out that way. I was the first one to respond to this particular question and I said the most important thing that you can do with Orbiter IV is to put it in a polar orbit and every scientist there agreed with me. Swetnick said, in effect, "I am sorry we can't do that. There isn't enough energy in the system to put it in a polar orbit." To myself I said I didn't believe that, but to Swetnik I said to "go back and tell them that the scientists feel that's the most important thing they can do and tell them to find a way of doing it." In about two weeks he came back and said they could do it. They did put Orbiter IV into a polar orbit and that has been the most important set of data on the Moon that we've got.

Doel:

Once these data were returned, were you actively involved with other members of the scientists who were part of the Orbiter project and analyze it?

Baldwin:

Only in the sense of taking the results that they got either in person or by correspondence or from publications on these. I did publish many papers using Orbiter and Ranger data. I am not a nuclear physicist. I have no way of going to a laboratory such as the "lunatic asylum" at Caltech and working with them and deriving answers to various questions. I have visited Wasserburg out at Caltech and have seen where he does his work. I met the people with him — Papanastassiou and some of the others. But Tera wasn't there though. I have taken their results and tried to apply them to what I know about the Moon and reach other interpretations or additional solutions to things that happened up there. I have gotten into major arguments with some of them. For example, Wasserburg and his group came out at the Fifth Lunar Science Conference in Houston with the hypothesis that there had been a terminal lunar cataclysm. They had said a little about it before so I was kind of prepared. (It was Papanastassiou who gave the paper.) I stood up and asked for four minutes. They gave me two. I took four and I lambasted his arguments and told him various reasons such as the necessary change in viscosity of the outer layers of the Moon and this, that and the other things; that there hadn't ever been a terminal lunar cataclysm. I got quite a little applause on that and Don Gault came up and said, "Say you seem to believe in impact cratering, don't you?" Don and I had been kidding back and forth about it. Right now people like Hartmann and Neukum and several others have backed me up completely on that. There never was a terminal lunar cataclysm. It has to be that what they were measuring was material scattered by the impact that produced Imbrium, possibly added to Orientale. In fact in a paper that I am going to be giving next month at the AAAS in Chicago, I call it erroneous conclusions drawn from excellent data. I visited Wasserburg in his lab about four years ago. He is still sticking to his guns. He is in a very small minority but he thinks the terminal cataclysm did happen. I don't, and I don't think there was a terminal terrestrial cataclysm either.

Doel:

Aside from these occasional meetings that you would have at Cal Tech — where the so-called lunatic asylum was it wasn't a sustained contact?

Baldwin:

Never was.

Doel:

When you would produce reports with other members of the Orbiter team, were your contributions on an individual level by and large or did it become more and more collaborative?

Baldwin:

No it has always been an individual effort with minor exceptions such as the Orbiter IV and the Caltech thing. I think it is a necessary concomitant of the fact that I had other responsibilities and I just couldn't take the time for it. I did publish several papers using Orbiter IV photographic data.

Doel:

Was it also something of your own style that you prefer to work alone?

Baldwin:

That is an awfully hard one to answer. During the war when I was with the Applied Physics Laboratory I was a regular part of a team. I wasn't working alone but there were things that I initiated like the anti-personnel use of the fuze that were alone. I think probably I work better alone than I would in a team on this kind of thing because, well I think my brain just works in that direction.

Doel:

It does for lots of people. Throughout the Apollo era — and I mean broadly now through the range of Apollo series — was it your sense that they were different scientific groups that had particular ideas on cratering origins?

Baldwin:

When Apollo came along many of the people who had been working in the field had come around to my points of view. There were geologists particularly who had different ideas, usually wrong. People like Jack Green — a geologist working at the University of Southern California. He stood up in many meetings that I attended and gave many arguments as to why the craters on the Moon were volcanic and that we could support ourselves on the Moon from the water taken from the lunar rocks and so on. The introduction to The Face of the Moon says the Moon is one of the driest places in the entire universe. As late as in the earliest 1970s I debated Jack Green on television — the impact theory against the volcanic theory. Arguments and the presentation of facts rolled off his back like water off a duck. He had his own ideas and was going to stick to them no matter what I said or what anybody else said. There were others like him.

Doel:

What sort of scientific following did Green have?

Baldwin:

He taught geology and I am sure he gave a new emphasis to his points of view to his students. I think the great majority of astronomers, and later geologists, came to realize that Green simply was barking up the wrong tree. I have a story and I think it is Green but I can't be sure. But in the 1970s someone asked a geologist who had the same point of view as Green what he was doing now. He said, "Keeping my mouth shut." When we finished our debate on television down in New York, he turned to me off camera and said, "Ralph, have you ever stopped to think that if you are wrong, my God! What a legacy." He was sincere.

Doel:

Did you know him well?

Baldwin:

I have probably seen him 25 times. I pulled a dirty trick on him once. There was a meeting at the New York Academy of Sciences and I was scheduled to give a paper. Something happened that I couldn't go but the paper was all written. Jack was putting the program on. I asked him if he could find somebody to read the paper for me and he read it himself. Afterward people told me there were giggles all through the talk.

Doel:

You discussed isostatic balance in many of your papers on the Moon in the late 1950s and early 1960s. Had you discussed this with geologists studying isostasy on the Earth? I noticed that you had cited Pascal's work in the 1930s.

Baldwin:

I never knew him. I read his publications on it and his theory. I never knew Airy, of course, and he had developed one of the theories of isostasy and I did not try to say which of the various isostatic theories was the correct one. I was simply saying that it occurred and these are the reasons why I think it occurred. I have talked to people in the Geology Department, like Henry Pollack down at Ann Arbor about it. I talked — this was later — with J. Melosh about it. I talked with Keith Runcorn in England. In fact, I gave a paper at the NATO conference in 1970 at Newcastle on "The Isostatic Situation on the Moon". I don't think any of them, except Urey and Kopal, really argued strongly against it. If you stop to analyze it there are too many rather obvious things. You find craters like Tycho or Copernicus which are relatively young, Aristarchus, and the features are sharp. The rims are high. The craters are deep. The crater bottom is normally somewhat rounded even though it may have a central peak in it. If you say erosion caused the features on the older craters to be more subdued I don't doubt that erosion actually occurred. But if you measure the volume of the subsurface portion of an old crater and the volume of the rim you will find that the volume of the crater decreases with increasing age of a crater, faster than the volume of the rim declines with increasing age. The factor is 2 to 4 over the age that we have. There is no way that I have been able to recognize whereby erosion will tumble material into a crater much faster than it will tumble it away from the outside. I have used that as a strong argument for existence of isostasy and the older the crater the greater the isostatic adjustments.

Doel:

By the 1960s were there still serious arguments about these crater measurements?

Baldwin:

If you carry this to an extreme, there are fragmental or partial remnants of craters existing in the very oldest terrains. They seem to have a maximum or a general rim height on the order of 300 meters. They don't disappear entirely. Then in the 1960s a man by the name of Frank Danes — at the University of Puget Sound — published a couple of papers and has had several since then, on the change in form of a crater which is actually, well not a true isostatic adjustment but a cold flow is what it really amounts to. When I gave my paper, in talking about some of these isostatic adjustments in 1962 at Blacksburg, he came up immediately afterward and started talking about some of his work. Then he sent me a paper which showed the changes in the crater Copernicus, with age. He made some assumptions on density and he had the dimensions and so on. Copernicus has a practically flat floor.

Doel:

These were assumptions about the pristine stage, right after formation?

Baldwin:

He took a typical brand new crater and postulated that it would settle. Then he would carry it on in the future — how far Copernicus would become modified. It depends, of course, on the viscosity. The viscosity and time are inversely related. Much later I asked him to extend his calculations even further, to the point where the crater is almost gone. It comes down to about a 300 meter rim, a trench inside the rim, and then a floor which may even be domed. It is just exactly what we find at old craters. It is a beautiful example of a mathematical model duplicating what actually occurs. Then when the contour map was published, showing the low areas in the circular Maria there is evidence that they have subsided under the influence of the load from the high density lava. The central parts of the basins are so deep; they are the deepest parts relative to a sphere but they also are the thickest parts of the lava. They are so deep that craters that were formed within the basins before the lava came don't project through. Out on what I call the "shelf area" they do project through, many of them at all of the big basins. The lavas there are thinner. I think there is no real argument now but what isostatic or cold flow actually did occur on the Moon and that the viscosity, while I worked in terms of some of my papers in effective viscosity, had to be highest at the surface; probably something of the order of 10 to the 31st poises and gradually working down. The average viscosity in the period, we'll say since Imbrium, was of the order of 10 to the 29th poises. But a few hundred million years earlier — around 4.25 or so which is a rough date for Humorum — the viscosity started at about 10 to the 24th. It increased as you came to the time of Imbrium. Then it increased very slowly to the present. I am going to do one more little thing along that line. I think people are coming to realize that the Moon's surface was once effectively fluid — way back. And, it couldn't have been a rather deep ocean or there would have been a long period of time before it solidified if it were several hundred kilometers deep there. The oldest craters that we can find are a little older than the Humorum basin and they are, as nearly as I can date them, about 4.3 billion years old. So if the Moon were formed at 4.55 you have only 250 million years. That magma layer had to be rather thin, but it was there. It came toward the end of the accretion period of the Moon. I am going to try to tie that in, I think, with the data that I have gotten earlier and published.

Doel:

In 1969 you had published one interesting argument on the range of ages of the Maria, using isostatic adjustments and made the calculation which had come just at the time the initial Apollo 11 results came back, which gave an older age for the Maria.

Baldwin:

Yes. Because in that particular paper I had no way of accounting for the fact that the viscosity was variable.

Doel:

Right. You had made an assumption.

Baldwin:

Yes, and there is a note at the end of that article about that.

Doel:

That note mentions that the two reviewers had nevertheless recommended that the paper be published.

Baldwin:

Yes, I don't know who they were. I made some assumptions and in the next two to three years I tried to see if I could determine what the viscosity was and did come up with some measures. They were very, very comparable to measures from the different point of view, or from theory a different point of view, as determined by Arkhani-Hamed.

Doel:

That name is not familiar to me.

Baldwin:

His name is Arkhani-Hamed. He is an Iranian and he was down at Houston. We both came up with viscosity increasing with time and of the order of 10 to the 28th at present. I now think that it is still higher at present

Doel:

You also mentioned, back in this 1969 article, that when you came up with the age of the Maria of about 400 million years —

Baldwin:

A little more than that, wasn't it?

Doel:

I believe that was the figure you had given. We can check on that.
[Upon checking, the age of the Maria found in the 1969 paper was 640,000,000 years].

Baldwin:

Wasserburg was going through the same mental process that I did and neither one of us took into account the variation of viscosity which makes a tremendous difference. That is one reason there was no terminal lunar cataclysm. When you change the viscosity of a substance over a very appreciable depth and you change it by 5-6-7 orders of magnitude, you don't do that in 10 million years.

Doel:

How closely involved were you with Shoemaker during the 1960s and 1970s?

Baldwin:

I had met Shoemaker several times. We corresponded off and on. I think we each had a good deal of respect for the other. I did not work with Shoemaker, or he with me. We did answer questions back and forth.

Doel:

One main thrust of Shoemaker's work in the early 1960s was to develop the various epochs of the lunar surface. Were you involved in the controversy over establishing those relative ages?

Baldwin:

I did nothing on that except to show in The Face of the Moon that there were structures which were older or younger than others, in various areas of the Moon. Then, I did not pursue that part. Shoemaker and Don Wilhelms did a great deal along that line.

Doel:

Was there a controversy over establishing the ages of various lunar units or was it more a matter of discussions among those who were connected with Shoemaker's circle over establishing the time scale?

Baldwin:

Shoemaker did not derive absolute ages. He would call it the Copernican Age, Eratosthenian Age, and so on. As far as I know, everybody accepted those as a very good approximation. They might argue over a little detail but in principle I think everybody thought they were correct. I certainly did.

Doel:

That's interesting to know.

Baldwin:

Did that agree with what you have found in talking with others?

Doel:

More or less. I think it seemed to be much more of a controversy to those who were intimately connected with Shoemaker but they were immediately involved in that.

Baldwin:

Wilhelms made a statement once that my observations were that the Seranitatis basin was formed, then the Imbrium basin and then the lavas — in that sequence. He made the statement that Ross Taylor told him that it was that observation of Baldwin that convinced him that the Moon had a stratigraphy of time periods defined on its surface from that. But that is as far as I carried it, just to point out that they were there. I can't do everything!

Doel:

You were working another full-time job and another career nearly all the time.

Baldwin:

Don't forget the moonlighting!

Doel:

Yes, you were moonlighting. By 1971, when you were addressing the ages of different units on the lunar surface, I sense that you became increasingly aware of work by different groups involved in asteroid research, as well as those who were actually doing counts. I am curious what you recall about this, what sense there was of that group?

Baldwin:

I have never met Gerald Hawkins but I have his papers and I have talked to him on the telephone, and we have corresponded back and forth. Similarly I have talked to Hugh Millard on those things and I went to Washington on one occasion and debated John A. O'Keefe on the origin of tektites. We got into the matter of tying in the frequencies of craters of different sizes and the abundances of meteorites of different sizes and trying to correlate them. I picked anybody's brains that I could find at that period of time and tried to bring the whole picture together. I think my 1964 paper on crater counts was a pretty good paper. Among other things, it makes the prediction that when you get to sub telescopic craters the abundances would go up substantially. I have forgotten who sent me a letter right after the first Ranger landed and said, "That was a pretty good prediction." You keep asking me questions and really I can't answer them because in addition to my own insights and conclusions, my work primarily was involved in reading everything that had been published that I could find and then analyzing it myself. There was very little cooperation or correlation with other individuals.

Doel:

That is an important point, and I am glad you emphasized it.

Baldwin:

I wasn't objecting to questions. I was just saying that I had to hem and haw when I tried to answer some of them.

Doel:

Most of the earlier work that you had developed appeared in astronomical periodicals. During the 1960s there became more varied outlets, including Journal of Geophysical Research (JGR).

Baldwin:

I stopped publishing there because they wanted some money from me each time. I didn't have any organization to pay for it but I am a member of the AGU and a fellow of the AGU but I am not choosing their publications except for a couple in Geophysical Research Letters.

Doel:

Yes. Do others feel that way about publishing in the JGR?

Baldwin:

I don't think so if they've got somebody else who is going to pay for it.

Doel:

You had said before that you became involved in the AGU (American Geophysical Union) during the 1960s. Do you recall any controversy over whether to make planetary science a separate section of the AGU as opposed to just integrating the work into existing sections?

Baldwin:

I wasn't involved in that.

Doel:

You may recall that Robert Jastrow was very much involved in favor of this idea, but others like Harry Wexler openly opposed it. Were you asked to consult at all in building the different institutes for lunar studies which came about during the 1960s such as the Lunar and Planetary Institute at Houston?

Baldwin:

No. I went to Houston. I had been down there several times and I have been through the rock room, where they have the lunar rocks. I have seen them. I have lectured down there but I have never been a consultant, really, for them about their structures.

Doel:

I didn't get a chance to ask you this a moment ago when we were talking about the planetesimals. Beals was also becoming involved with the rate of flux (see Note on p. 78) with asteroid contributions toward impact.

Baldwin:

Everybody is interested in that field who studies it at all. They begin to question where these things come from and how they correlate with what is falling today and what can we learn for the future. I think one of the things that brings out most violently is this 65 million year old impact. That would have made the 1906 earthquake in San Francisco infinitesimal in comparison and I personally think we are very foolish in not setting up a formal program to search for these Apollo type asteroids of any size and get their orbits so we know if they will or will not in the foreseeable future, hit the earth. If we find out ahead of time — and we might not — and we keep the space program going, we might be able to do something about it.

Doel:

You would want something in addition to currents efforts?

Baldwin:

You've got Gehrels working on it, Shoemaker working on it and they are doing tremendous work but it isn't a work specifically for that. What I am saying, in effect, is right now we don't have another Apollo rocket. If Gehrels or Shoemaker finds an asteroid, when they calculate its orbit and find it is going to hit the Earth — and it's a fairly good-sized one — if it is 3 or 4 or 5 or 10 years away we could probably even now do something about it. But if it is two months away there isn't anything we could about it. If we were ready and had a spaceship backup maybe we could use it, maybe we could go out there and detonate a nuclear device against the asteroid to change its orbit to one that would miss the earth. We might be able to save an American State or if it is big enough, one of the nations, OR if it is big enough — the world! You see even something like Eros — which doesn't come within 14-15 million miles of the Earth now — ultimately will hit one of the planets because of perturbations. That is way out in the future. I don't know how anybody can look at the geologic record and not realize that we are very vulnerable. We are going to be hit by some big ones. If it is only once every 5,000 or 10,000 years, or 50,000 years — something like the Arizona crater is going to happen. That should be stopped, if possible. If something really big comes in, it will be stopped or else. I don't know if the human race could continue to exist if that 65 million year old thing struck today. I am told that no form of life — land life — weighing over 55 pounds survived that. Maybe just our young children would.

Doel:

It is certainly a difficult question for science policy.

Baldwin:

The time scales are so long that the politics are "Well, it may happen but it won't happen right away."

Doel:

It is always analogous, I think, to why New York City doesn't have (until very recently) earthquake codes. One thing that was very striking in the 1960s, early 1970s was the reaction of many Soviet scientists to the idea of crater formation. Throughout the 1960s many Soviet scientists had rejected the impact theory for lunar craters.

Baldwin:

They were slow in coming around, but people like Levin who were on the right side of the fence right from the beginning, and Florenski. But many of the Soviets just didn't accept it. I think my work — if I stop and think back on it — in the early stages I was trying to find out what happened. As soon as we got that down to what I thought was a reasonable solution my next question was how did it happen and then the next question — where I spent an awful lot of time — is when did it happen? I think that is the thought process that I have gone through.

Doel:

Do you have speculations on why the Soviets opposed the crater arguments?

Baldwin:

I really don't have an answer for that unless — and this is pure supposition — their responses were guided by their geologists. Our geologists were way late in coming around.

Doel:

You have a criticism toward your paper by G. S. Steinberg?

Baldwin:

Yes. I responded to him. He was a volcanologist and I think that is the reason he went after me.

Doel:

Do you have any contacts with him aside from this exchange?

Baldwin:

He used to send Christmas cards and that is about the last — I haven't talked to him. I haven't written to him for years.

Doel:

Are there other areas, other things that we have not talked about with your lunar research that you wanted to bring up? Areas that we passed over?

Baldwin:

The things we haven't covered are the work since the 1970s. I have concentrated, in large measure, on the "when" question. When did various things happen? That has been much of my interest. I was very, very interested when the Alvarez's and their compatriots came up with the idea of the impact 65 million years ago. I went out to San Francisco and visited with Luis Alvarez. I had lunch with him and told him I was going to get involved in it. He encouraged me to do so and then unfortunately he died some months later. I collected the data that had been gathered on iridium abundances and instead of trying to put it on a flat map I made a 16" plastic globe and inked in the latitude and longitude lines, particularly for the northern hemisphere. I plotted these abundances as the heights of rods which I glued to the surface. Each rod was placed at the position it would have had 65 million years ago, taking into account continental drift. It was quite evident that the northern hemisphere had about three times as much iridium as the south.

Doel:

This is even taking into account that more sites were potentially sampled in the northern hemisphere?

Baldwin:

No, taking into account the average abundance at every site. Of course, there are relatively few locations where the Cretaceous-Tertiary boundary is exposed. It is spotty world-wide. Also the tallest rods were more or less centered around the North Pole. I told Walter Alvarez — the son and a couple of others — that my interpretation would be that the thing hit somewhere in northern Canada, maybe up in the islands. Then Bohor and Izett came out with their grains of quartz sand imbedded in the 65 million year layer. When you plot the maximum size of the crystal —

Doel:

This is the shocked quartz?

Baldwin:

This is the shocked quartz which is found worldwide; wherever they find the iridium at the K-T boundary they will find the shocked quartz. They have even found it in New Zealand. Those quartz grains are so big — most of them — that any one of the pieces reported would fall through the atmosphere to the surface in a day from any height. Consequently, they had to be emplaced in ballistic trajectories and this explosion had to be violent enough to in effect blow the atmosphere away and let some of the ejecta go out. The largest pieces of quartz — up to .58 millimeter in maximum dimension — are all found in the United States and Canada. It is at least consistent with the idea of a northern Canadian source area. I also contacted Mike Dence, and Mike and Walter Alvarez didn't commit themselves in any way, shape or manner. I didn't ask them to. But Mike furnished me with maps of Canada — geologic maps and contour maps of all Canada, and the islands. I went through the whole darn bunch of them and on the very last map I found a structure that looked quite interesting. It is a semi-circle with a peninsula coming out from the south — I can show you a map of it before we are through here — on the north shore of Canada, half in water and half on land (I am not sure what's in the water yet) about as far east of the Alaska border as Point Barrow is west — 500 miles maybe. It is east of the MacKenzie Delta. A year ago August I went up there to look at it. It is 180 km across. It is right in the size range that the K-T crater should be. The area on this peninsula is composed mostly of flat-lying rock. It does not resemble a central peak as I visualize it. That is the one big thing arguing against this. The structural dimensions are right. The age is right. The shape is right. Isostatic adjustments should bring it back to about what it is now. At present I am having a computer man in Grand Rapids take the data which I have collected, on the depth of the water and there seems to me — this is preliminary — that there is a suggestion of a ring going all the way around. Now, very low. If so I think the chances are pretty darn good that that is an old impact crater. It may not be the one but it is about the right age. It is a most interesting thing and I have one paper coming out in the December issue of the Journal of Royal Astronomical Society of Canada and, in fact, I sent the page proof back yesterday. I probably will put another one out when I find out what the sub-water area really is like. That is the last paper that I have in mind. I don't know whether I will ever do anymore although I may do this one on the viscosity changes, trying to tie it into the magma area. I haven't done any work on that at all. I think it is about time to hang up the gloves.

Doel:

It should be an interesting story to follow that through.

Baldwin:

I am publishing it saying a "possible" giant asteroid and saying these are the arguments for and against. If it isn't an impact crater, what in blazes is it because everybody I have talked to said, "That can't be!" But nobody will tell me how it was produced. That includes Mike Dence, Walter Alvarez, and Bob Dietz.

Doel:

What are their feelings on it at the moment? Do they agree it is an astrobleme?

Baldwin:

No.

Doel:

They feel it is not?

Baldwin:

They don't know. They won't commit themselves. I can't blame them. Many of them will say "No, I don't think it is but...."

Doel:

It is certainly an on-going debate.

Baldwin:

It's fun. I hired a float plane and picked it up in Inuvik. It is a little town on the MacKenzie Delta. It is the center of the oil investigation group up there in northern Canada. We flew out and landed on several lakes in the central peak area. The water was about 38 degrees. The soil was all washed away and nothing but rounded rocks up to shore. We couldn't get the plane all the way in so I would have to walk out in that 38 degree water for it. We were up practically 70 degrees north. I took some pictures of it, which I can show you, a couple of them. On the way back we flew out over the south rim which is over 300 meters high. It looks like, on the maps, an escarpment. It is 6 km wide and 300 meters high. That is a 3 degree slope and it is about what you would expect on a big crater like this. It doesn't look highly eroded although there are erosional features on it. We saw about 30 musk ox from the plane. We got almost back to Inuvik and that thing out in front of the plane that goes around suddenly stopped going around! We made a very nice, dead stick landing in a convenient lake. We kept on trying to start the motor. There was some gunk that had gotten in the gas tank. Just as the plane we radioed for came in, we took off and flew over the hill and into the lake where we wanted to be, and then back into shore. It is rather an interesting feeling to have a plane's motor stop in mid-air.

Doel:

I'm sure that must have been.

Baldwin:

Those light planes have a pretty good gliding angle. I don't know how far they can glide but we had no problem.

Doel:

Getting near to the end of the questions that I had wanted to ask you in this session, I will ask again if anything else had come to mind that you wanted to discuss.

Baldwin:

Not right now.

Doel:

I was interested in learning more about your personal outlook — whether you had, through your life, any strong religious affiliation or feelings or any other strong convictions?

Baldwin:

I will put it this way. I am not a Christian. I am not a Muslim or a Hindu, but I am not an atheist. The more I read about modern religions or even ancient religions, the more childish they seem. I sat in this chair last summer and I read the entire Koran — every page of it. There are 114 articles in it and every one of them says the same darn thing in a different way. It is incredible to me that people can get as fanatic about it as they are. And, similarly with Christianity. If you want to analyze it, Christianity and the New Testament have no books in it that are younger than 20 years after Christ died. All of them were written after Paul had his so-called vision on the road to Tarsus. I have some books which analyze Paul's writings — two of them in fact. Basically one of them concludes that the writings of Paul are deliberately made to establish a religion and that his stories have relatively little connection with the life of Jesus as it probably was. The man has concluded that Jesus was a — what's the term for one of the teachers — a Pharisee — and that his philosophy, his actions, would not be quite what Paul was recording. The other books — the four Gospels — the first one was written 30 years after Christ died in the early 60s and then going on to John, which is probably around 105-110 A.D., Christ supposedly died about 33 A.D. There are many points of similarity but when you analyze them there are many points of disagreement in them. It looks very much as though they are individuals' memories of what somebody once said many years before and that not one of the people who wrote the Gospels or any of the other books of the New Testament ever saw Christ. What we have is a religion which is defined primarily by people around 330 A.D. at the Council of Nicea when they said this is holy testimony, this is not, and so on. Even then they had major squabbles between the Aryans and the Athanasians over "Was Christ God, was the Trinity meaningful, or was God by himself?" To me there are so many questions that a thorough analysis of the Bible arouses, that I am not willing to make a commitment that this is a religion that I should follow. There are many things about the Bible — the Golden Rule for example — that I am very much in favor of. I think it is entirely possible that there was a God who started this whole universe but I can't see that an interpretation of this universe by people who knew very little about it and who were not consistent in their writings, whether it is Mohammed or whether it is the Koran or whether it is the authors of the various books of the Bible — New Testament only — there is no way for me to accept it. I know many people don't want to think about it but they do want to accept it. That is fine. If it satisfies them, I don't argue with that in any way, shape, or manner. But I have a great deal of trouble even in trying to conceive of the existence of a God. I cannot deny that there was(is) one but when you can't communicate in our universe faster than the speed of light — and there are all sorts of attempts being made trying to show how it could be done but none successful — I doubt very much that any god I can conceive of could simultaneously note the falling of a sparrow on the earth and the falling of an ipswich on a planet 3 billion light years away. It just doesn't make sense. That is all I am saying. I would be more apt, I think, to think that this universe — if it were produced by a being — is more apt to be a physics experiment that got away than an intentional formation of a universe which has evolved continually for something close to 16 billion years. If you want to really look at it from the point of view of a god, who created the God? Where did he come from? Did he exist in a universe which didn't exist before 16 billion years ago?

Doel:

It is the ultimate epistemology question.

Baldwin:

Right. Well, I have ranted a little too far perhaps there.

Doel:

No, I think that was a very fitting conclusion. I would like to thank you very much for doing this long session and we will, of course — and this should go on tape — not make this tape available to anyone or its transcript without your expressed knowledge and approval, as defined in the permission forms that we will be sending you.

Baldwin:

Once we have come to an agreement on the tape, then whether I am here to give permission or not you would have permission.

Notes added by Dr. Baldwin:

Numerous scientists, geologists, geophysicists, astronomers and others have written me, saying that my pioneering work has had a major effect on their work.

Right from the beginning it was clear to me that the moon was not alone in space. This sounds obvious, but it was important. The moon was always the companion of the earth. The environments of these two bodies were essentially the same. What happened to the moon from the outside, happened in spades to the earth. I also recognized in 1949 that we ultimately would find that Mars and Mercury were cratered. Venus was cloud-covered and the giant planets were too far away.

Also in 1949 I proposed that giant impacts on the earth might have been the cause of the great extinctions of life that had occurred in the past. This probably has been confirmed. The Alvarez impact 65 million years ago seems to be real and its association with a major extinction of life on the earth can no longer be doubted. Several other findings of meteoritic iridium seem to coincide with certain lesser Cenozoic extinctions and probably with the giant extinction at the end of the Permian Period.

In a 1971 paper in Icarus I predicted that the solar system had an early, not from the asteroid belt, group of objects in elliptical orbits, often ranging from Mercury out to at least Saturn, that was responsible for the early massive crater-forming impacts and that the planets and their satellites thus were all in similar environments. Craters younger than Imbrium were largely from asteroids.

The net effect of this was that astronomers and geologists began to realize that catastrophism had been a normal part of the history of the earth and all the solar system. This contrasted with Lyell's hypothesis that had held the stage for perhaps 150 years, that all of the earth's features could be explained by processes known to be operative at present. This meant a slow evolutionary history. We now know that many normal catastrophic events have been superimposed on the quiescent earth and, of course, the other solar system bodies. Sometimes these catastrophes affected the entire planet or satellite.

Hoyt called this a new conception, a scientific revolution, in his book, Coon Mountain Controversies.